Question

In: Chemistry

Which of these indicators would be appropriate for the following titrations. Methyl Orange pKa = 4.1...

Which of these indicators would be appropriate for the following titrations.

Methyl Orange pKa = 4.1   
Bromthymol Blue pKa = 7.0
Phenolphthalein pKa = 9.3

ethylamine titrated with hydrochloric acid

perchloric acid titrated with lithium hydroxide

formic acid titrated with sodium hydroxide

sodium acetate titrated with nitric acid

Solutions

Expert Solution

The best indicator is the one whose pKa matches with the pH of the titration at equivalence point.

A) Titration of ethylamine with HCl

The conjugate acid of a weak base is a strong acid. So the pH at equivalence point would be acidic.

The indicator which is best for this would be thus,

Methyl orange with pKa = 4.1

B) perchloric acid titration with LiOH

Both perchloric acid and LiOh are strong acid and strong base, respectively.

Thus the pH at equivalence point would be +7 neutral

The best indicator for this titration would be,

Bromothymol Blue pKa = 7.0

C) Formic acid titrated with NaOH

Titration of weak acid as formic acid with strong base NaOH

The conjugate base of weak acid is a strong base. So the solution would be basic at equivalence point.

The best indicator for this titration would be,

Phenolphthalein

D) Sodium acetate with nitric acid

At equivalence point the pH of this solution would be slightly acidic.

The best indicator for this titration would be,

Methyl orange pKa = 4.1


Related Solutions

Methyl orange changes from red at pH 3.1 to yellow at pH 4.4. Would methyl orange...
Methyl orange changes from red at pH 3.1 to yellow at pH 4.4. Would methyl orange be a suitable indicator for the titration of propanoic acid (pKa=4.87, Ka=1.34x10^-5) with 0.01 M NaOH? Explain. Phenolphthalein changes from colorless at pH 8.0 to pink at pH 9.6. Would phenolphthalein be a suitable indicator for the titration of propanoic acid with 0.01 M NaOH? Explain.
Which of the pH indicators from the following table would be most appropriate for the titration...
Which of the pH indicators from the following table would be most appropriate for the titration of 100 mL of 0.30 M acetic acid (Ka = 1.8 x 10-5 ) with 0.15 M sodium hydroxide?
Explain which of the following indicators would be appropriate for a weak acid-strong base titration?
  1) A pH meter is standardized at what three pHs?   2) The initial pH of the acetic acid-NaOH titration curve was _________. 3) Explain which of the following indicators would be appropriate for a weak acid-strong base titration? Indicator pH of color change Bromcresol green 3.8 - 5.4 Bromothymol blue 6.0 - 7.6 Phenolphthalein 8.0 - 9.6
1. Which chemical is formed upon the addition of HCl to methyl orange? Name (not IUPAC)...
1. Which chemical is formed upon the addition of HCl to methyl orange? Name (not IUPAC) and draw it. 2. Which chemical is formed upon the addition of NaOH to methyl orange? Name (not IUPAC) and draw it. Explain how you know. 3. Which chemical is formed upon the addition of HCl to phenolphthalein? Name (not IUPAC) and draw it. 4. Which chemical is formed upon the addition of NaOH to phenolphthalein? Name (not IUPAC) and draw it. Explain how...
In relation to the Balanced Scorecard, which of the following Key Performance Indicators (KPI) would be...
In relation to the Balanced Scorecard, which of the following Key Performance Indicators (KPI) would be useful in evaluating a company's customer perspective of improving customer satisfaction for long term success?
Define the following and provide examples of Financial ratio outcomes which would be positive indicators of...
Define the following and provide examples of Financial ratio outcomes which would be positive indicators of a company’s: 1) Solvency 2) Liquidity
9.) Which of the following titrations results in an acidic solution at the equivalent point? a.)...
9.) Which of the following titrations results in an acidic solution at the equivalent point? a.) acetic acid titrated w/ NaOH b.) hydrochloric acid titrated w/ KOH c.) C5H5N titrated w/ HBr d.) NaOH titrated w/ nitric acid 10.) Which combination of solutions is the BEST choice for making a buffer solution? a.) equal volumes of 1 M ammonia and 0.001 M ammonium chloride. b.) equal volumes of 0.5 M HCl and 0.5 M NaOH. c.) equal volumes of 0.5...
In which of the following cases would it not be appropriate to use ?t procedures to...
In which of the following cases would it not be appropriate to use ?t procedures to make inferences about ?μ using ?¯x¯ ? We have a sample of size ?=20 and x has a right‑skewed distribution with an outlier. We have a sample of size ?=8 and x has a Normal distribution. We have a sample of size ?=60 and x has a right‑skewed distribution with no outliers. We have a sample of size ?=20 and x has a Normal...
Which of the following scenarios would it be appropriate to use a normal approximation for the...
Which of the following scenarios would it be appropriate to use a normal approximation for the sampling distribution of the sample proportion? Select one: A researcher wishes to find the probability that more than 60% of a sample of undergraduate students from UNC will be female. She samples the first 42 students that walk into the gym on Monday morning. The population proportion of undergraduate females at UNC is known to be 60.1%. A researcher wishes to find the probability...
Which of the following titrations results in a basic solution at the equivalence point? Select one:...
Which of the following titrations results in a basic solution at the equivalence point? Select one: A. NaCN titrated with HCl B. HCl titrated with NH3 C. HCN titrated with NaOH D. HCl titrated with NaOH
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT