Analytical Chemistry

Question 1

Someone spilled concentrated sulfuric acid on the floor of a chemistry laboratory. Which of the following is the best action to do?

Answer 1

Spray solid sodium bicarbonate over the acid

Question 2

Which of the following oxides is basic?

Answer 2

Metallic Oxides
Na2O

Question 3

When the equation below is balanced, which of the following ratios is true?

Question 4

It is defined as the sum of all titratable bases to a pH of approximately 4.5. It has units of equivalents per liter or normality.

Answer 4

Alkalinity

Question 5

What are the coefficients for HCl and ICl if the equation below is balanced?

Answer 5

25, 13

Question 6

Consider the titration of 20.00-mL portion of 0.50 M NH3 with 0.5 M HCl titrant. What is the pH after 10.00 mL of titrant was added? Kb = 1.8x10-5

Answer 6

9.2553

Question 7

Consider the titration of 20.00-mL portion of 0.50 M NH3 with 0.5 M HCl titrant. What is the pH at the equivalence point? Kb = 1.8x10-5

Answer 7

4.9287

Question 8

A 50.0 mL sample of sulfuric acid was diluted to 1.00 L. A 20.00-mL portion of the diluted sulfuric acid was analyzed by titrating with standardized sodium hydroxide in which 25.00 mL of 1M base was used. What is the molar concentration of the acid?

Answer 8

12.5 M

Question 9

The pH of a water sample is measured to be 7.5. The concentration of the bicarbonate was measured to be 1.3x10-3 M. For carbonic acid, pKa1 is 6.3 and pKa2 is 10.33. What is the concentration of carbonic acid?

Answer 9

8.2 x10^-5 M

Question 10

The pH of a water sample is measured to be 7.5. The concentration of the bicarbonate was measured to be 1.3x10^-3 M. For carbonic acid, pKa1 is 6.3 and pKa2 is 10.33. What is the concentration of carbonate?

Answer 10

1.9 x10^-6 M

Question 11

Consider a solution of calcium carbonate that is initially supersaturated with Ca2+ and CO3^2-, such that the concentrations of each are both 1.35x1019^-3 M. The pKsp of calcium carbonate (aragonite) is 8.34. What is the equilibrium concentration of Ca2+?

Answer 11

5.00 x 10^-5

Question 12

A water sample has an alkalinity of 200 mg/L as CaCO3. Ca^2+ concentration is 160 mg/L and the Mg^2+ is 40 mg/L. The pH is 8.1. Find the total hardness.

Answer 12

566.67 mg/L

Question 13

A water sample has an alkalinity of 200 mg/L as CaCO3. Ca2+ concentration is 160 mg/L
and the Mg2+ is 40 mg/L. The pH is 8.1. Find the noncarbonate hardness

Answer 13

366.67 mg/L

Question 14

The concentration of H2O2 in an antiseptic solution was determined by titration with 0.0200 M KMnO4 solution. 20.00 mL of the peroxide solution was diluted to 250.0 mL. 20.00 mL aliquots of the diluted solution were acidified and titrated with potassium permanganate solution. An average titer of 18.93 mL was required. Calculate the concentration of the hydrogen peroxide in the solution

Answer 14

0.5915 M

Question 15

A sample is to be analyzed for its chloride content by precipitating and weighing AgCl. What weight of sample would have to be taken so that the weight of precipitate is equal to the %Cl in the sample/

Answer 15

24.74 g

Question 16

Carbonate Hardness and non carbonate difference

Answer 16

Carbonate hardness is temporary hardness while non carbonate hardness is permanent hardness