142:
2181:
2169:
2197:
1550:
409:
2145:
2157:
849:
36:
1841:
1969:
In acid-base titrations, an unfitting pH indicator may induce a color change in the indicator-containing solution before or after the actual equivalence point. As a result, different equivalence points for a solution can be concluded based on the pH indicator used. This is because the slightest color
879:
Tabulated below are several common laboratory pH indicators. Indicators usually exhibit intermediate colors at pH values inside the listed transition range. For example, phenol red exhibits an orange color between pH 6.8 and pH 8.4. The transition range may shift slightly depending on the
800:
value plus or minus one. This assumes that solutions retain their color as long as at least 10% of the other species persists. For example, if the concentration of the conjugate base is 10 times greater than the concentration of the acid, their ratio is 10:1, and consequently the pH is
1970:
change of the indicator-containing solution suggests the equivalence point has been reached. Therefore, the most suitable pH indicator has an effective pH range, where the change in color is apparent, that encompasses the pH of the equivalence point of the solution being titrated.
1961: ± 1, but this range can be extended by using mixtures of two or more indicators. Because indicators have intense absorption spectra, the indicator concentration is relatively low, and the indicator itself is assumed to have a negligible effect on pH.
1637:
1561:
An indicator may be used to obtain quite precise measurements of pH by measuring absorbance quantitatively at two or more wavelengths. The principle can be illustrated by taking the indicator to be a simple acid, HA, which dissociates into H and A.
1938:
647:
of conjugate acid/base to concentration of the acidic/basic indicator determines the pH (or pOH) of the solution and connects the color to the pH (or pOH) value. For pH indicators that are weak electrolytes, the
2043:). The color changes between red in acid solutions and blue in alkalis. The term 'litmus test' has become a widely used metaphor for any test that purports to distinguish authoritatively between alternatives.
1982:
family of compounds. They are red in acidic solutions and blue in basic. Anthocyanins can be extracted with water or other solvents from a multitude of colored plants and plant parts, including from leaves
141:
1642:
840:, both species confer a color. While pH indicators work efficiently at their designated pH range, they are usually destroyed at the extreme ends of the pH scale due to undesired side reactions.
2180:
2055:
available to these plants, turning the flowers blue. In alkaline soils, these reactions cannot occur and therefore aluminium is not taken up by the plant. As a result, the flowers remain pink.
832:
For optimal accuracy, the color difference between the two species should be as clear as possible, and the narrower the pH range of the color change the better. In some indicators, such as
1836:{\displaystyle {\begin{aligned}A_{x}&=\varepsilon _{{\ce {HA}}}^{x}+\varepsilon _{{\ce {A-}}}^{x}\\A_{y}&=\varepsilon _{{\ce {HA}}}^{y}+\varepsilon _{{\ce {A-}}}^{y}\end{aligned}}}
2168:
880:
concentration of the indicator in the solution and on the temperature at which it is used. The figure on the right shows indicators with their operation range and color changes.
868:
is frequently used. Sometimes, a blend of different indicators is used to achieve several smooth color changes over a wide range of pH values. These commercial indicators (e.g.,
471:
755:
value, the concentration of the conjugate base is greater than the concentration of the acid, and the color associated with the conjugate base dominates. If pH is below the p
876:) are used when only rough knowledge of pH is necessary. For a titration, the difference between the true endpoint and the indicated endpoint is called the indicator error.
2196:
526:
In and of themselves, pH indicators are usually weak acids or weak bases. The general reaction scheme of acidic pH indicators in aqueous solutions can be formulated as:
466:
of the solution to change depending on the pH. Indicators can also show change in other physical properties; for example, olfactory indicators show change in their
786:
value, but a pH range exists where a mixture of colors is present. This pH range varies between indicators, but as a rule of thumb, it falls between the p
1143:
1003:
955:
1122:
979:
931:
443:) of the solution can be determined visually or spectroscopically by changes in absorption and/or emission properties. Hence, a pH indicator is a
2315:
1852:
1201:
2435:
864:
choice (determination) of color, pH indicators are susceptible to imprecise readings. For applications requiring precise measurement of pH, a
474:). Solutions with a pH value below 7.0 are considered acidic and solutions with pH value above 7.0 are basic. Since most naturally occurring
1951:. The observed spectrum (green) is the sum of the spectra of HA (gold) and of A (blue), weighted for the concentration of the two species.
3664:
3643:
334:
275:
395:
3753:
2021:, used by alchemists in the Middle Ages and still readily available, is a naturally occurring pH indicator made from a mixture of
2404:
3279:
815: + 1. Conversely, if a 10-fold excess of the acid occurs with respect to the base, the ratio is 1:10 and the pH is p
100:
17:
72:
2428:
1944:
649:
3340:
2267:
856:
pH indicators are frequently employed in titrations in analytical chemistry and biology to determine the extent of a
499:
498:. Moreover, pH indicators form one of the three main types of indicator compounds used in chemical analysis. For the
119:
79:
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2051:
flowers can change color depending on soil acidity. In acid soils, chemical reactions occur in the soil that make
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1947:. In fact, a whole spectrum may be used for this purpose. The process is illustrated for the indicator
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2174:
A gradient of red cabbage extract pH indicator from acidic solution on the left to basic on the right
1943:
If measurements are made at more than two wavelengths, the concentrations and can be calculated by
166:
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503:
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231:
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These are two equations in the two concentrations and . Once solved, the pH is obtained as
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241:
93:
8:
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1954:
When a single indicator is used, this method is limited to measurements in the pH range p
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dissolved in water is yellow under acidic and reddish brown under alkaline conditions
1948:
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741:
value of the indicator, both species are present in a 1:1 ratio. If pH is above the p
424:
251:
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where, "HInd" is the acidic form and "Ind" is the conjugate base of the indicator.
475:
440:
324:
186:
176:
3012:
2015:, to form a crude pH indicator is a popular introductory chemistry demonstration.
1631:
at the two wavelengths are simply the sum of the absorbances due to each species.
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1614:
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171:
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1933:{\displaystyle \mathrm {pH} =\mathrm {p} K_{\mathrm {a} }+\log {\frac {}{}}}
3714:
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3393:
3259:
3254:
3182:
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2004:
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involving one or more redox reactions as the basis of chemical analysis).
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2012:
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1978:
Many plants or plant parts contain chemicals from the naturally colored
836:, one of the species is colorless, whereas in other indicators, such as
3633:
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3149:
3124:
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Purple cauliflower soaked in baking soda (left) and vinegar (right).
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2008:
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1613:
must also have been determined by previous experiment. Assuming
3042:
2114:
2022:
2018:
2295:. Translated by Irving, Harry (1st English ed.). London:
3659:
3638:
2063:
2011:). Extracting anthocyanins from household plants, especially
1992:
487:
463:
3213:
2512:
2040:
1996:
467:
436:
265:
156:
636:
where "IndOH" stands for the basic form and "Ind" for the
579:
Vice versa for basic pH indicators in aqueous solutions:
772:
Usually, the color change is not instantaneous at the p
727:
and basicity constant, states that when pH equals the p
432:
221:
1855:
1640:
470:. The pH value of a neutral solution is 7.0 at 25°C (
1973:
506:
is preferred, whereas the third compound class, the
60:. Unsourced material may be challenged and removed.
1932:
1835:
3764:
2328:
2329:Adams, Elliot Q.; Rosenstein, Ludwig. (1914).
2429:
2290:
389:
2331:"The Color and Ionization of Crystal-Violet"
2312:Complexometry with EDTA and related reagents
3389:Nuclear magnetic resonance (NMR) instrument
1599:of the two species HA and A at wavelengths
2436:
2422:
2058:Another natural pH indicator is the spice
490:, pH indicators find many applications in
396:
382:
2354:
2066:and reddish brown when in presence of an
1544:
120:Learn how and when to remove this message
3754:Instruments used in medical laboratories
3235:
2443:
2335:Journal of the American Chemical Society
2262:(3rd ed.). New York: W.H. Freeman.
1548:
847:
407:
3270:Inductively coupled plasma (ICP) device
2377:
1617:to be obeyed, the measured absorbances
27:Chemical added to show pH of a solution
14:
3765:
3318:Transmission electron microscope (TEM)
2255:
1467:
3595:
3414:
3234:
2894:
2455:
2417:
2309:
2251:
2249:
2247:
2035:is literally from 'colored moss' in
1964:
1392:Phenolphthalein (second transition)
58:adding citations to reliable sources
29:
852:pH measurement with indicator paper
462:Normally, the indicator causes the
24:
3313:Scanning electron microscope (SEM)
2062:. It turns yellow when exposed to
1878:
1868:
1860:
1857:
1557:at different stages of protonation
25:
3794:
2394:
2244:
1974:Naturally occurring pH indicators
3358:Thermogravimetric analyzer (TGA)
3168:Nuclear magnetic resonance (NMR)
2195:
2179:
2167:
2155:
2143:
723:The equations, derived from the
140:
34:
3415:
455:O) or hydrogen ions (H) in the
45:needs additional citations for
2371:
2322:
2303:
2291:Schwarzenbach, Gerold (1957).
2284:
1924:
1916:
1911:
1896:
1802:
1787:
1764:
1756:
1708:
1693:
1670:
1662:
843:
650:HendersonâHasselbalch equation
472:standard laboratory conditions
13:
1:
2895:
2237:
769:value, the converse is true.
502:of metal cations, the use of
412:pH indicators: a graphic view
1457:
1454:
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987:
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963:
942:
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915:
427:added in small amounts to a
7:
2456:
2378:Zumdahl, Steven S. (2009).
2314:(3rd ed.). Poole, UK:
2259:Exploring chemical analysis
2210:
10:
3799:
3596:
2382:(6th ed.). New York:
2256:Harris, Daniel C. (2005).
2162:Hydrangea in alkaline soil
1572:acid dissociation constant
3751:
3702:
3652:
3619:
3606:
3602:
3591:
3562:
3531:
3513:Time-domain reflectometer
3475:
3427:
3423:
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3366:
3326:
3303:
3280:Liquid chromatograph (LC)
3247:
3243:
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3191:
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3097:
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3003:
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2949:
2933:
2907:
2903:
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2773:
2707:
2619:
2544:
2466:
2462:
2451:
2310:West, T. S. (1969).
2293:Complexometric Titrations
521:
504:complexometric indicators
2384:Houghton Mifflin Company
2190:acts as an pH indicator.
1142:Screened methyl orange (
232:Self-ionization of water
217:Hammett acidity function
3348:Melting-point apparatus
2729:Cryogenic storage dewar
3285:Mass spectrometer (MS)
3275:Gas chromatograph (GC)
2150:Hydrangea in acid soil
2025:species, particularly
1934:
1837:
1558:
1553:Absorption spectra of
1545:Precise pH measurement
1119:Screened methyl orange
853:
413:
3773:Equilibrium chemistry
3660:Acid-resistant gloves
3341:differential scanning
2048:Hydrangea macrophylla
1935:
1838:
1581:, must be known. The
1552:
851:
500:quantitative analysis
411:
247:Frustrated Lewis pair
207:Equilibrium chemistry
197:Dissociation constant
167:Acidâbase homeostasis
3237:Analytical chemistry
2739:Laminar flow cabinet
2445:Laboratory equipment
2407:4 March 2022 at the
1945:linear least squares
1853:
1638:
910:(Methyl violet 10B)
496:analytical chemistry
242:Lewis acid catalysis
54:improve this article
18:Acid-base indicators
3609:Personal protective
2518:MekerâFisher burner
2401:Long indicator list
2386:. pp. 319â324.
2380:Chemical Principles
2347:10.1021/ja02184a014
2232:Universal indicator
1828:
1783:
1734:
1689:
1469:Universal Indicator
1375:(first transition)
870:universal indicator
822: â 1 or p
808: + 1 or p
652:can be written as:
3452:Function generator
3435:Bench power supply
3374:Analytical balance
3135:Ostwald viscometer
3130:Graduated cylinder
2869:Inoculation needle
2316:BDH Chemicals Ltd.
2028:Roccella tinctoria
1999:petals); berries (
1930:
1833:
1831:
1805:
1767:
1711:
1673:
1559:
1429:Alizarine Yellow R
1240:Bromocresol purple
1221:Azolitmin (litmus)
854:
640:of the indicator.
414:
162:Acidâbase reaction
3760:
3759:
3747:
3746:
3743:
3742:
3720:Fire extinguisher
3710:Biosafety cabinet
3698:
3697:
3587:
3586:
3583:
3582:
3518:Transistor tester
3508:Spectrum analyzer
3406:
3405:
3402:
3401:
3226:
3225:
3222:
3221:
3098:Measuring devices
2920:Soxhlet extractor
2886:
2885:
2882:
2881:
2834:Spectrophotometer
2829:Pipeclay triangle
2581:Mortar and pestle
2356:2027/uc1.b3762873
2299:. pp. 29â46.
2139:
2138:
1965:Equivalence point
1949:bromocresol green
1928:
1922:
1903:
1814:
1794:
1775:
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1720:
1700:
1681:
1668:
1583:molar absorbances
1570:The value of the
1555:bromocresol green
1542:
1541:
1465:
1464:
1316:Naphtholphthalein
1164:Bromocresol green
1144:second transition
1004:second transition
956:second transition
860:. Because of the
858:chemical reaction
476:organic compounds
425:chemical compound
406:
405:
252:Chiral Lewis acid
130:
129:
122:
104:
16:(Redirected from
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3617:
3616:
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3603:
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3498:Network analyzer
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3424:
3412:
3411:
3245:
3244:
3232:
3231:
2905:
2904:
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2891:
2874:Inoculation loop
2744:Microtiter plate
2684:Test tube holder
2576:Magnetic stirrer
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2463:
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2452:
2438:
2431:
2424:
2415:
2414:
2388:
2387:
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2369:
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2358:
2341:(7): 1452â1473.
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2300:
2297:Methuen & Co
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1259:Bromothymol blue
1123:first transition
1062:Bromophenol blue
980:first transition
932:first transition
883:
882:
829: â 1.
725:acidity constant
719:
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560:
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546:
544:
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512:redox titrations
508:redox indicators
484:carboxylic acids
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391:
384:
365:Non-nucleophilic
192:Buffer solutions
177:Acidity function
144:
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3735:Solvent cabinet
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3665:Eyewash station
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3613:
3611:equipment (PPE)
3610:
3598:
3579:
3558:
3527:
3471:
3462:Pulse generator
3428:Control devices
3419:
3398:
3362:
3328:Thermochemistry
3322:
3299:
3239:
3218:
3187:
3144:
3110:Conical measure
3093:
3062:
2999:
2968:
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2929:
2899:
2878:
2859:Test tube brush
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2754:Picotiter plate
2717:
2703:
2699:Lab drying rack
2658:Extension clamp
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2409:Wayback Machine
2397:
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2318:pp. 14â82.
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2096:pink to purple
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1604:
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1547:
1472:
1410:Thymolphthalein
1373:Phenolphthalein
1354:Cresolphthalein
1348:reddish-purple
952:Malachite green
928:Malachite green
898:
893:
846:
834:phenolphthalein
828:
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554:
553:
551:
549:
542:
539:
538:
537:
535:
533:
524:
457:Arrhenius model
454:
402:
227:Proton affinity
152:Acceptor number
135:Acids and bases
126:
115:
109:
106:
63:
61:
51:
39:
28:
23:
22:
15:
12:
11:
5:
3796:
3786:
3785:
3780:
3775:
3758:
3757:
3752:
3749:
3748:
3745:
3744:
3741:
3740:
3738:
3737:
3732:
3730:Safety cabinet
3727:
3722:
3717:
3712:
3706:
3704:
3700:
3699:
3696:
3695:
3693:
3692:
3690:Safety goggles
3687:
3685:Safety glasses
3682:
3680:Nitrile gloves
3677:
3675:Medical gloves
3672:
3667:
3662:
3656:
3654:
3650:
3649:
3647:
3646:
3641:
3636:
3631:
3626:
3620:
3614:
3607:
3600:
3599:
3589:
3588:
3585:
3584:
3581:
3580:
3578:
3577:
3572:
3570:Alligator clip
3566:
3564:
3560:
3559:
3557:
3556:
3551:
3546:
3544:Soldering iron
3541:
3535:
3533:
3529:
3528:
3526:
3525:
3520:
3515:
3510:
3505:
3500:
3495:
3490:
3488:Logic analyzer
3485:
3479:
3477:
3473:
3472:
3470:
3469:
3464:
3459:
3454:
3449:
3448:
3447:
3445:Voltage source
3442:
3440:Current source
3431:
3429:
3421:
3420:
3408:
3407:
3404:
3403:
3400:
3399:
3397:
3396:
3391:
3386:
3381:
3379:Colony counter
3376:
3370:
3368:
3364:
3363:
3361:
3360:
3355:
3350:
3345:
3344:
3343:
3332:
3330:
3324:
3323:
3321:
3320:
3315:
3309:
3307:
3301:
3300:
3298:
3297:
3292:
3287:
3282:
3277:
3272:
3267:
3262:
3257:
3251:
3249:
3241:
3240:
3228:
3227:
3224:
3223:
3220:
3219:
3217:
3216:
3211:
3206:
3201:
3195:
3193:
3189:
3188:
3186:
3185:
3180:
3175:
3170:
3165:
3160:
3154:
3152:
3146:
3145:
3143:
3142:
3137:
3132:
3127:
3122:
3117:
3112:
3107:
3101:
3099:
3095:
3094:
3092:
3091:
3086:
3081:
3076:
3070:
3068:
3064:
3063:
3061:
3060:
3055:
3050:
3045:
3040:
3035:
3030:
3025:
3020:
3018:Vacuum (Dewar)
3015:
3009:
3007:
3001:
3000:
2998:
2997:
2992:
2987:
2982:
2976:
2974:
2970:
2969:
2967:
2966:
2961:
2955:
2953:
2947:
2946:
2944:
2943:
2937:
2935:
2931:
2930:
2928:
2927:
2922:
2917:
2911:
2909:
2901:
2900:
2888:
2887:
2884:
2883:
2880:
2879:
2877:
2876:
2871:
2866:
2861:
2856:
2851:
2846:
2841:
2836:
2831:
2826:
2821:
2816:
2811:
2806:
2801:
2796:
2791:
2788:
2783:
2777:
2775:
2771:
2770:
2768:
2767:
2764:
2761:
2756:
2751:
2746:
2741:
2736:
2731:
2726:
2720:
2718:
2716:
2715:
2712:
2708:
2705:
2704:
2702:
2701:
2696:
2691:
2689:Test tube rack
2686:
2681:
2678:
2673:
2670:
2665:
2664:Funnel support
2662:
2659:
2656:
2651:
2646:
2641:
2637:
2635:
2633:
2632:
2629:
2624:
2620:
2617:
2616:
2614:
2613:
2608:
2603:
2598:
2593:
2588:
2583:
2578:
2573:
2571:Liquid whistle
2568:
2563:
2557:
2555:
2553:
2552:
2549:
2545:
2542:
2541:
2539:
2538:
2536:Vacuum dry box
2533:
2528:
2523:
2520:
2515:
2510:
2505:
2500:
2498:Heating mantle
2495:
2490:
2485:
2483:Alcohol burner
2479:
2477:
2475:
2474:
2471:
2467:
2460:
2459:
2449:
2448:
2441:
2440:
2433:
2426:
2418:
2412:
2411:
2396:
2395:External links
2393:
2390:
2389:
2370:
2321:
2302:
2283:
2268:
2242:
2241:
2239:
2236:
2235:
2234:
2229:
2224:
2219:
2212:
2209:
2208:
2207:
2201:
2194:
2192:
2185:
2178:
2176:
2173:
2166:
2164:
2161:
2154:
2152:
2149:
2142:
2137:
2136:
2135:reddish brown
2133:
2130:
2124:
2123:
2120:
2117:
2111:
2110:
2107:
2104:
2098:
2097:
2094:
2091:
2084:
2083:
2082:High pH color
2080:
2077:
2007:); and stems (
1975:
1972:
1966:
1963:
1958:
1941:
1940:
1926:
1918:
1913:
1907:
1898:
1892:
1889:
1886:
1880:
1875:
1870:
1866:
1862:
1859:
1844:
1843:
1826:
1818:
1808:
1804:
1798:
1789:
1786:
1781:
1770:
1766:
1758:
1755:
1752:
1750:
1746:
1742:
1738:
1737:
1732:
1724:
1714:
1710:
1704:
1695:
1692:
1687:
1676:
1672:
1664:
1661:
1658:
1656:
1652:
1648:
1644:
1643:
1627:
1620:
1609:
1602:
1596:
1589:
1578:
1568:
1567:
1546:
1543:
1540:
1539:
1538:Violet/Indigo
1536:
1535:Strong alkali
1533:
1529:
1528:
1525:
1522:
1518:
1517:
1514:
1511:
1507:
1506:
1505:Orange/Yellow
1503:
1500:
1496:
1495:
1492:
1489:
1485:
1484:
1481:
1478:
1471:
1466:
1463:
1462:
1459:
1456:
1453:
1450:
1448:Indigo carmine
1444:
1443:
1440:
1437:
1434:
1431:
1425:
1424:
1421:
1418:
1415:
1412:
1406:
1405:
1402:
1399:
1396:
1393:
1389:
1388:
1385:
1382:
1379:
1376:
1369:
1368:
1365:
1362:
1359:
1356:
1350:
1349:
1346:
1343:
1340:
1337:
1331:
1330:
1329:greenish-blue
1327:
1324:
1321:
1318:
1312:
1311:
1308:
1305:
1302:
1299:
1293:
1292:
1289:
1286:
1283:
1280:
1274:
1273:
1270:
1267:
1264:
1261:
1255:
1254:
1251:
1248:
1245:
1242:
1236:
1235:
1232:
1229:
1226:
1223:
1217:
1216:
1213:
1210:
1207:
1204:
1198:
1197:
1194:
1191:
1188:
1185:
1179:
1178:
1175:
1172:
1169:
1166:
1160:
1159:
1156:
1153:
1150:
1147:
1139:
1138:
1135:
1132:
1129:
1126:
1115:
1114:
1111:
1108:
1105:
1102:
1096:
1095:
1092:
1089:
1086:
1083:
1077:
1076:
1073:
1070:
1067:
1064:
1058:
1057:
1054:
1051:
1048:
1045:
1043:Methylene blue
1039:
1038:
1035:
1032:
1029:
1026:
1020:
1019:
1016:
1013:
1010:
1007:
996:
995:
992:
989:
986:
983:
972:
971:
968:
965:
962:
959:
948:
947:
944:
941:
938:
935:
924:
923:
920:
917:
914:
911:
908:Gentian violet
904:
903:
902:High pH color
900:
895:
890:
887:
874:Hydrion papers
845:
842:
826:
819:
812:
805:
797:
790:
783:
776:
766:
759:
752:
745:
738:
731:
721:
720:
715:
709:
702:
698:
687:
686:
685:
680:
674:
666:
660:
638:conjugate acid
634:
633:
630:
623:
616:
609:
600:
593:
584:
574:
573:
570:
563:
556:
547:
540:
531:
523:
520:
510:, are used in
452:
404:
403:
401:
400:
393:
386:
378:
375:
374:
373:
372:
367:
362:
357:
352:
347:
342:
337:
335:BrĂžnstedâLowry
329:
328:
321:
320:
319:
318:
313:
308:
303:
298:
293:
288:
283:
278:
276:BrĂžnstedâLowry
270:
269:
262:
261:
260:
259:
254:
249:
244:
239:
234:
229:
224:
219:
214:
209:
204:
199:
194:
189:
184:
179:
174:
169:
164:
159:
154:
146:
145:
137:
136:
128:
127:
69:"PH indicator"
42:
40:
33:
26:
9:
6:
4:
3:
2:
3795:
3784:
3781:
3779:
3776:
3774:
3771:
3770:
3768:
3755:
3750:
3736:
3733:
3731:
3728:
3726:
3723:
3721:
3718:
3716:
3713:
3711:
3708:
3707:
3705:
3701:
3691:
3688:
3686:
3683:
3681:
3678:
3676:
3673:
3671:
3668:
3666:
3663:
3661:
3658:
3657:
3655:
3651:
3645:
3644:Safety shower
3642:
3640:
3637:
3635:
3632:
3630:
3627:
3625:
3622:
3621:
3618:
3615:
3612:
3605:
3601:
3594:
3590:
3576:
3573:
3571:
3568:
3567:
3565:
3561:
3555:
3554:Wire stripper
3552:
3550:
3547:
3545:
3542:
3540:
3537:
3536:
3534:
3530:
3524:
3521:
3519:
3516:
3514:
3511:
3509:
3506:
3504:
3501:
3499:
3496:
3494:
3491:
3489:
3486:
3484:
3481:
3480:
3478:
3474:
3468:
3465:
3463:
3460:
3458:
3455:
3453:
3450:
3446:
3443:
3441:
3438:
3437:
3436:
3433:
3432:
3430:
3426:
3422:
3418:
3413:
3409:
3395:
3392:
3390:
3387:
3385:
3384:Spiral plater
3382:
3380:
3377:
3375:
3372:
3371:
3369:
3365:
3359:
3356:
3354:
3351:
3349:
3346:
3342:
3339:
3338:
3337:
3334:
3333:
3331:
3329:
3325:
3319:
3316:
3314:
3311:
3310:
3308:
3306:
3302:
3296:
3293:
3291:
3288:
3286:
3283:
3281:
3278:
3276:
3273:
3271:
3268:
3266:
3263:
3261:
3258:
3256:
3253:
3252:
3250:
3248:Compositional
3246:
3242:
3238:
3233:
3229:
3215:
3212:
3210:
3207:
3205:
3202:
3200:
3197:
3196:
3194:
3190:
3184:
3181:
3179:
3176:
3174:
3171:
3169:
3166:
3164:
3161:
3159:
3156:
3155:
3153:
3151:
3147:
3141:
3138:
3136:
3133:
3131:
3128:
3126:
3123:
3121:
3118:
3116:
3113:
3111:
3108:
3106:
3103:
3102:
3100:
3096:
3090:
3087:
3085:
3082:
3080:
3077:
3075:
3072:
3071:
3069:
3065:
3059:
3056:
3054:
3051:
3049:
3046:
3044:
3041:
3039:
3036:
3034:
3031:
3029:
3026:
3024:
3021:
3019:
3016:
3014:
3011:
3010:
3008:
3006:
3002:
2996:
2993:
2991:
2988:
2986:
2983:
2981:
2978:
2977:
2975:
2971:
2965:
2962:
2960:
2957:
2956:
2954:
2952:
2948:
2942:
2939:
2938:
2936:
2932:
2926:
2923:
2921:
2918:
2916:
2913:
2912:
2910:
2906:
2902:
2898:
2893:
2889:
2875:
2872:
2870:
2867:
2865:
2862:
2860:
2857:
2855:
2852:
2850:
2847:
2845:
2842:
2840:
2837:
2835:
2832:
2830:
2827:
2825:
2822:
2820:
2817:
2815:
2812:
2810:
2807:
2805:
2802:
2800:
2797:
2795:
2792:
2790:Balance brush
2789:
2787:
2784:
2782:
2779:
2778:
2776:
2772:
2766:Weighing dish
2765:
2763:Weighing boat
2762:
2760:
2757:
2755:
2752:
2750:
2747:
2745:
2742:
2740:
2737:
2735:
2732:
2730:
2727:
2725:
2722:
2721:
2719:
2713:
2710:
2709:
2706:
2700:
2697:
2695:
2692:
2690:
2687:
2685:
2682:
2679:
2677:
2674:
2671:
2669:
2666:
2663:
2660:
2657:
2655:
2654:Burette clamp
2652:
2650:
2647:
2645:
2642:
2639:
2638:
2636:
2630:
2628:
2625:
2622:
2621:
2618:
2612:
2609:
2607:
2604:
2602:
2599:
2597:
2594:
2592:
2589:
2587:
2584:
2582:
2579:
2577:
2574:
2572:
2569:
2567:
2564:
2562:
2559:
2558:
2556:
2550:
2547:
2546:
2543:
2537:
2534:
2532:
2529:
2527:
2524:
2521:
2519:
2516:
2514:
2511:
2509:
2506:
2504:
2501:
2499:
2496:
2494:
2491:
2489:
2488:Bunsen burner
2486:
2484:
2481:
2480:
2478:
2472:
2469:
2468:
2465:
2461:
2454:
2450:
2446:
2439:
2434:
2432:
2427:
2425:
2420:
2419:
2416:
2410:
2406:
2402:
2399:
2398:
2385:
2381:
2374:
2366:
2362:
2357:
2352:
2348:
2344:
2340:
2336:
2332:
2325:
2317:
2313:
2306:
2298:
2294:
2287:
2279:
2275:
2271:
2269:0-7167-0571-0
2265:
2261:
2260:
2252:
2250:
2248:
2243:
2233:
2230:
2228:
2225:
2223:
2222:Fecal pH test
2220:
2218:
2215:
2214:
2204:
2198:
2193:
2189:
2182:
2177:
2170:
2165:
2158:
2153:
2146:
2141:
2140:
2134:
2131:
2129:
2126:
2125:
2121:
2118:
2116:
2113:
2112:
2108:
2105:
2103:
2100:
2099:
2095:
2092:
2089:
2086:
2085:
2081:
2079:Low pH color
2078:
2075:
2074:
2071:
2069:
2065:
2061:
2056:
2054:
2050:
2049:
2044:
2042:
2038:
2034:
2030:
2029:
2024:
2020:
2016:
2014:
2010:
2006:
2002:
1998:
1994:
1990:
1986:
1981:
1971:
1962:
1957:
1952:
1950:
1946:
1905:
1890:
1887:
1884:
1873:
1864:
1849:
1848:
1847:
1824:
1816:
1806:
1796:
1784:
1779:
1768:
1753:
1751:
1744:
1740:
1730:
1722:
1712:
1702:
1690:
1685:
1674:
1659:
1657:
1650:
1646:
1634:
1633:
1632:
1630:
1623:
1616:
1612:
1605:
1595:
1588:
1584:
1577:
1573:
1565:
1564:
1563:
1556:
1551:
1537:
1534:
1531:
1530:
1526:
1523:
1520:
1519:
1515:
1512:
1509:
1508:
1504:
1501:
1498:
1497:
1493:
1490:
1487:
1486:
1482:
1479:
1476:
1475:
1470:
1460:
1451:
1449:
1446:
1445:
1441:
1432:
1430:
1427:
1426:
1422:
1413:
1411:
1408:
1407:
1403:
1394:
1391:
1390:
1386:
1377:
1374:
1371:
1370:
1366:
1357:
1355:
1352:
1351:
1347:
1338:
1336:
1333:
1332:
1328:
1319:
1317:
1314:
1313:
1309:
1300:
1298:
1295:
1294:
1290:
1281:
1279:
1276:
1275:
1271:
1262:
1260:
1257:
1256:
1252:
1243:
1241:
1238:
1237:
1233:
1224:
1222:
1219:
1218:
1214:
1205:
1203:
1202:Methyl purple
1200:
1199:
1195:
1186:
1184:
1181:
1180:
1176:
1167:
1165:
1162:
1161:
1157:
1148:
1145:
1141:
1140:
1136:
1127:
1124:
1120:
1117:
1116:
1112:
1103:
1101:
1100:Methyl orange
1098:
1097:
1093:
1084:
1082:
1079:
1078:
1074:
1065:
1063:
1060:
1059:
1055:
1046:
1044:
1041:
1040:
1036:
1027:
1025:
1024:Methyl yellow
1022:
1021:
1017:
1008:
1005:
1001:
998:
997:
993:
984:
981:
977:
974:
973:
969:
960:
957:
953:
950:
949:
945:
936:
933:
929:
926:
925:
921:
912:
909:
906:
905:
901:
896:
891:
889:Low pH color
888:
885:
884:
881:
877:
875:
871:
867:
863:
859:
850:
841:
839:
835:
830:
825:
818:
811:
804:
796:
789:
782:
775:
770:
765:
758:
751:
744:
737:
730:
726:
697:
693:
692:
690:
669:
659:
655:
654:
653:
651:
646:
645:concentration
643:The ratio of
641:
639:
582:
581:
580:
577:
529:
528:
527:
519:
517:
513:
509:
505:
501:
497:
493:
489:
485:
481:
477:
473:
469:
465:
460:
458:
450:
447:detector for
446:
442:
438:
434:
430:
426:
423:
419:
410:
399:
394:
392:
387:
385:
380:
379:
377:
376:
371:
368:
366:
363:
361:
358:
356:
353:
351:
348:
346:
343:
341:
338:
336:
333:
332:
331:
330:
326:
323:
322:
317:
314:
312:
309:
307:
304:
302:
299:
297:
294:
292:
289:
287:
284:
282:
279:
277:
274:
273:
272:
271:
267:
264:
263:
258:
255:
253:
250:
248:
245:
243:
240:
238:
235:
233:
230:
228:
225:
223:
220:
218:
215:
213:
210:
208:
205:
203:
200:
198:
195:
193:
190:
188:
185:
183:
180:
178:
175:
173:
172:Acid strength
170:
168:
165:
163:
160:
158:
155:
153:
150:
149:
148:
147:
143:
139:
138:
134:
133:
124:
121:
113:
102:
99:
95:
92:
88:
85:
81:
78:
74:
71: â
70:
66:
65:Find sources:
59:
55:
49:
48:
43:This article
41:
37:
32:
31:
19:
3715:Fire blanket
3653:Eye and hand
3639:Rubber apron
3503:Oscilloscope
3467:Potentiostat
3394:Plate reader
3290:pH indicator
3289:
3260:CHN analyzer
3255:AutoAnalyzer
3048:Round-bottom
2941:Boston round
2804:Filter paper
2759:Refrigerator
2676:Retort stand
2644:Clamp holder
2640:Beaker clamp
2606:Vortex mixer
2601:Stirring rod
2596:Static mixer
2526:Teclu burner
2379:
2373:
2338:
2334:
2324:
2311:
2305:
2292:
2286:
2258:
2102:Anthocyanins
2057:
2046:
2045:
2032:
2026:
2017:
2005:blackcurrant
1987:); flowers (
1977:
1968:
1955:
1953:
1942:
1845:
1625:
1618:
1607:
1600:
1593:
1586:
1575:
1569:
1560:
1524:Weak alkali
1491:Strong acid
1480:Description
1395:purple-pink
1387:purple-pink
1149:purple-grey
1137:purple-grey
1085:blue-violet
922:blue-violet
878:
855:
831:
823:
816:
809:
802:
794:
787:
780:
773:
771:
763:
756:
749:
742:
735:
728:
722:
695:
688:
657:
642:
635:
578:
575:
525:
480:electrolytes
461:
418:pH indicator
417:
415:
202:Donor number
116:
107:
97:
90:
83:
76:
64:
52:Please help
47:verification
44:
3703:Other items
3629:Face shield
3476:Measurement
3457:Galvanostat
3417:Electronics
3367:Other items
3353:Thermometer
3336:Calorimeter
3265:Colorimeter
3209:Gas syringe
3192:Other items
3120:Eye dropper
2995:Watch glass
2980:Evaporating
2959:Cold finger
2774:Other items
2680:Screw clamp
2672:Pinch clamp
2661:Flask clamp
2611:Wash bottle
2566:Homogenizer
2217:Chromophore
2188:Anthocyanin
2031:. The word
2013:red cabbage
2001:blueberries
1985:red cabbage
1980:anthocyanin
1297:Neutral red
1000:Thymol blue
976:Thymol blue
844:Application
422:halochromic
182:Amphoterism
3783:Indicators
3767:Categories
3634:Respirator
3575:Test probe
3493:Multimeter
3305:Microscopy
3125:Eudiometer
3089:Separatory
3058:Volumetric
3023:Erlenmeyer
2951:Condensers
2915:DeanâStark
2864:Wire brush
2824:Microscope
2819:Centrifuge
2794:Cork borer
2749:Petri dish
2724:Agar plate
2711:Containers
2694:Wire gauze
2531:Water bath
2493:Desiccator
2238:References
2076:Indicator
1615:Beer's law
1566:HA â H + A
1502:Weak acid
1414:colorless
1404:colorless
1378:colorless
1358:colorless
1335:Cresol red
1278:Phenol red
1183:Methyl red
1056:dark blue
1047:colorless
970:colorless
897:Transition
892:Transition
886:Indicator
862:subjective
838:methyl red
516:titrations
482:, such as
360:Superbases
306:Superacids
212:Extraction
80:newspapers
3778:Titration
3725:Fume hood
3670:Glove box
3523:Voltmeter
2908:Apparatus
2897:Glassware
2786:Autoclave
2781:Aspirator
2734:Incubator
2668:Iron ring
2591:Sonicator
2561:Chemostat
2503:Hot plate
2365:0002-7863
2227:Nitrazine
2088:Hydrangea
2053:aluminium
2037:Old Norse
1906:−
1891:
1817:−
1807:ε
1797:−
1769:ε
1723:−
1713:ε
1703:−
1675:ε
1477:pH range
1320:pale red
1081:Congo red
899:high end
478:are weak
449:hydronium
257:ECW model
237:Titration
3624:Lab coat
3549:Tweezers
3539:Heat gun
3295:pH meter
3204:Bell jar
3084:Dropping
3038:Florence
3028:Fernbach
2990:Syracuse
2849:Scoopula
2799:Crucible
2508:Lab oven
2405:Archived
2278:54073810
2211:See also
2203:Turmeric
2128:Turmeric
2090:flowers
2060:turmeric
1989:geranium
1513:Neutral
894:low end
866:pH meter
445:chemical
441:basicity
429:solution
110:May 2012
3563:General
3483:Ammeter
3183:Thistle
3140:Pipette
3115:Cuvette
3105:Burette
3074:BĂŒchner
3067:Funnels
3053:Schlenk
3033:Fleaker
3013:BĂŒchner
2934:Bottles
2854:Spatula
2844:Stopper
2814:Forceps
2714:Storage
2631:Holders
2551:Shakers
2522:Striker
2470:Heaters
2457:General
2132:yellow
2068:alkalis
2009:rhubarb
1521:8 â 11
1483:Colour
1461:yellow
1433:yellow
1367:purple
1339:yellow
1310:yellow
1282:yellow
1263:yellow
1253:purple
1244:yellow
1206:purple
1196:yellow
1168:yellow
1113:yellow
1066:yellow
1037:yellow
1009:yellow
994:yellow
937:yellow
913:yellow
718:
706:
694:pOH = p
683:
671:
492:biology
451:ions (H
437:acidity
431:so the
345:Organic
291:Organic
286:Mineral
94:scholar
3597:Safety
3199:Beaker
3178:Thiele
3163:Cragie
3158:Drying
3079:Hirsch
3043:Retort
3005:Flasks
2973:Dishes
2964:Liebig
2925:Kipp's
2839:Splint
2649:Tripod
2627:Clamps
2623:Stands
2586:Shaker
2548:Mixers
2473:Dryers
2363:
2276:
2266:
2115:Litmus
2033:litmus
2023:lichen
2019:Litmus
1532:11-14
1516:Green
1499:3 â 6
1215:green
1158:green
961:green
946:green
656:pH = p
522:Theory
488:amines
355:Strong
301:Strong
96:
89:
82:
75:
67:
3532:Tools
3150:Tubes
2985:Petri
2122:blue
2109:blue
2093:blue
2064:acids
2039:(see
1995:, or
1993:poppy
1527:Blue
1458:13.0
1455:11.4
1452:blue
1439:12.0
1436:10.2
1423:blue
1420:10.5
1401:13.0
1398:12.0
1384:10.0
1272:blue
1234:blue
1177:blue
1075:blue
1018:blue
967:14.0
964:11.6
701:+ log
583:IndOH
464:color
420:is a
350:Oxide
340:Lewis
327:types
316:Solid
296:Oxide
281:Lewis
268:types
101:JSTOR
87:books
3214:Vial
3173:Test
2809:File
2513:Kiln
2361:ISSN
2274:OCLC
2264:ISBN
2119:red
2106:red
2041:Litr
1997:rose
1624:and
1606:and
1592:and
1494:Red
1488:1-3
1442:red
1417:9.3
1381:8.3
1364:9.8
1361:8.2
1345:8.8
1342:7.2
1326:8.7
1323:7.3
1307:8.0
1304:6.8
1301:red
1291:red
1288:8.0
1285:6.4
1269:7.6
1266:6.0
1250:6.8
1247:5.2
1231:8.3
1228:4.5
1225:red
1212:5.4
1209:4.8
1193:6.2
1190:4.4
1187:red
1174:5.4
1171:3.8
1155:4.2
1152:3.2
1134:3.2
1131:0.0
1128:red
1110:4.4
1107:3.1
1104:red
1094:red
1091:5.0
1088:3.0
1072:4.6
1069:3.0
1053:9.0
1050:5.0
1034:4.0
1031:2.9
1028:red
1015:9.6
1012:8.0
991:2.8
988:1.2
985:red
943:2.0
940:0.0
919:2.0
916:0.0
872:and
793:or p
779:or p
762:or p
748:or p
734:or p
631:(aq)
624:(aq)
585:(aq)
571:(aq)
564:(aq)
532:(aq)
530:HInd
494:and
486:and
468:odor
370:Weak
325:Base
311:Weak
266:Acid
187:Base
157:Acid
73:news
2351:hdl
2343:doi
2070:.
1888:log
1574:, p
665:log
621:Ind
617:(l)
601:(l)
568:Ind
548:(l)
439:or
56:by
3769::
2403:,
2359:.
2349:.
2339:36
2337:.
2333:.
2272:.
2246:^
2003:,
1991:,
1921:HA
1774:HA
1761:HA
1680:HA
1667:HA
1590:HA
1585:,
1510:7
1146:)
1125:)
1006:)
982:)
958:)
934:)
703:10
689:or
667:10
663:+
628:OH
626:+
619:+
603:â
587:+
566:+
550:â
534:+
459:.
433:pH
416:A
222:pH
2437:e
2430:t
2423:v
2367:.
2353::
2345::
2280:.
1983:(
1959:a
1956:K
1925:]
1917:[
1912:]
1902:A
1897:[
1885:+
1879:a
1874:K
1869:p
1865:=
1861:H
1858:p
1825:y
1813:A
1803:]
1793:A
1788:[
1785:+
1780:y
1765:]
1757:[
1754:=
1745:y
1741:A
1731:x
1719:A
1709:]
1699:A
1694:[
1691:+
1686:x
1671:]
1663:[
1660:=
1651:x
1647:A
1628:y
1626:A
1621:x
1619:A
1610:y
1608:λ
1603:x
1601:λ
1597:A
1594:Δ
1587:Δ
1579:a
1576:K
1121:(
1002:(
978:(
954:(
930:(
827:b
824:K
820:a
817:K
813:b
810:K
806:a
803:K
801:p
798:b
795:K
791:a
788:K
784:b
781:K
777:a
774:K
767:b
764:K
760:a
757:K
753:b
750:K
746:a
743:K
739:b
736:K
732:a
729:K
712:/
699:b
696:K
677:/
661:a
658:K
614:O
610:2
605:H
598:O
594:2
589:H
561:O
557:3
552:H
545:O
541:2
536:H
514:(
453:3
435:(
397:e
390:t
383:v
123:)
117:(
112:)
108:(
98:·
91:·
84:·
77:·
50:.
20:)
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