Titration and Buffers

Question 1

50.00 mL of hydrochloric acid is titrated with a 2.368 M magnesium hydroxide solution.

Since the concentration of magnesium hydroxide is known, magnesium hydroxide is the —–

and should be transferred to a —– .

Since the concentration of hydrochloric acid is unknown, hydrochloric acid is the —-0.498 M

and 50.00 mL should be transferred to a —– .

Answer 1

titrant
buret
analyte
Erlenmeyer flask

Question 2

50.00 mL of hydrochloric acid is titrated with a 2.368 M magnesium hydroxide solution. The end point is reached with 5.26 mL of magnesium hydroxide solution. What is the concentration of the hydrochloric acid?

Answer 2

0.498 M

Question 3

A 0.335 M solution of sulfuric acid, H2SO4 (aq), is used to titrate 25.00 mL of a cesium hydroxide solution.

Since the concentration of sulfuric acid is known, sulfuric acid is the —–

and should be transferred to a —– .

Since the concentration of the cesium hydroxide solution is unknown, cesium hydroxide is the —–

and 25.00 mL should be transferred to a ——- .

Answer 3

titrant
buret
analyte
Erlenmeyer flask

Question 4

A 0.335 M solution of sulfuric acid, H2SO4 (aq), is used to titrate 25.00 mL of a cesium hydroxide solution. The titration requires 41.58 mL of sulfuric acid to reach the end point. What is the concentration of the cesium hydroxide solution?

Answer 4

1.11 M

Question 5

A cabinet in the laboratory is labeled “HCl and NaOH.” All the bottles in the cabinet contain solutions of either hydrochloric acid, HCl (aq), or sodium hydroxide, NaOH (aq). The bottles are missing labels to indicate the substance or its concentration. You are tasked with determining that information.

Answer 5

analytes

Erlenmeyer flasks .

Question 6

Using a pipette, you collect a 25.00 mL sample from five bottles. To each sample, you add an indicator called bromothymol blue, which is yellow at low pH values and turns blue around pH values of 6.0 to 7.5. Some samples are yellow and some are blue.

Answer 6

The yellow samples are acidic .

The blue samples are basic .

Question 7

You prepare new solutions of 1.00 M HCl and 1.00 M NaOH.

Answer 7

The 1.00 M HCl solution is a(n) acid

that will be used as a(n) titrant

with the samples that are blue ,

and so should be transferred to a buret .

The 1.00 M NaOH solution is a(n) base

that will be used as a(n) titrant

with the samples that are yellow ,

and so should be transferred to a buret

Question 8

You create a data table to keep track of the titration of each sample.

Answer 8

Sample 1

Substance: HCl

Substance in Buret: NaOH

Sample 2

Substance: HCl

Substance in Buret: NaOH

Sample 3

Substance: HCl

Substance in Buret: NaOH

Sample 4

Substance: NaOH

Substance in Buret: HCl

Sample 5

Substance: NaOH

Substance in Buret: HCl

Question 9

You fill the burets and collect the titration data below.

Calculate the concentration of each sample.

Answer 9

Sample 1 Concentration
0.823 M

Sample 2 Concentration
0.113 M

Sample 3 Concentration
0.677 M

Sample 4 Concentration
0.278 M

Sample 5 Concentration
0.779 M