Analytical Chemistry

Question 1

A solution is basic if:

Answer 1

[OH-] > [H+]

Question 2

Water at room temperature usually has a slightly acidic pH. This is largely attributed to what compound(s)?

Answer 2

Carbonic acid

Question 3

When benzoic acid dissolves in water, it partially reacts with water and ionizes to form benzoate and hydronium ions. In this reaction, what is the conjugate acid?

Answer 3

Hydronium ions

Question 4

Define a salt in terms of acid and base.

Answer 4

A salt is a compound (other than water) produced by the reaction of an acid and a base.

Question 5

When a can of soda is opened and CO2 is released to the atmosphere, what is the resultant pH of the soda?

Answer 5

Increases

Question 6

Which of the following pairs will form a buffer solution in the course of a titration?

Answer 6

Acetic acid, sodium hydroxide

Question 7

Buffer capacity is maximum when:

Answer 7

pH = pKa

Question 8

Which of the following acids would be most suitable for preparing a buffer of pH 3.1?

Answer 8

Sulfanilic acid, pKa = 3.23

Question 9

A solution of cation gives a crimson red flame. This flame test is a confirmatory test for:

Answer 9

Sr(2+)

Question 10

A solution of cation gives a blue-green flame. This flame test is a confirmatory test for:

Answer 10

Cu

Question 11

A solution of cation gives a brick red flame. This flame test is a confirmatory test for:

Answer 11

Ca(2+)

Question 12

A solution of cation gives a bright orange flame. This flame test is a confirmatory test for:

Answer 12

C(2+)

Question 13

A solution of cation gives a bright green flame. This flame test is a confirmatory test for:

Answer 13

B(3+)

Question 14

A solution of cation gives a blue flame. This flame test is a confirmatory test for:

Answer 14

As(3+)

Question 15

A solution of cation gives a silver white flame. This flame test is a confirmatory test for:

Answer 15

Al(3+)

Question 16

What is the color of nickel chloride?

Answer 16

yellow

Question 17

Substances whose solutions change color due to changes in pH

Answer 17

Indicator

Question 18

Redox couple for chemical analysis involving permanganate in acidic medium

Answer 18

MnO₄⁻ → Mn²⁺

Question 19

Redox couple for chemical analysis involving permanganate in basic medium (5 < pH < 9)

Answer 19

MnO₄⁻ → MnO₂

Question 20

Redox couple for chemical analysis involving dichromate

Answer 20

Cr₂O₇²⁻ → Cr³⁺

Question 21

Redox couple for chemical analysis involving iron

Answer 21

Fe³⁺ → Fe²⁺

Question 22

Redox couple for chemical analysis involving copper

Answer 22

Cu²⁺ → Cu⁺

Question 23

Redox couple for chemical analysis involving cerium

Answer 23

Ce⁴⁺ → Ce³⁺

Question 24

Redox couple for chemical analysis involving chromate in acidic medium

Answer 24

H₂C₂O₄ → CO₂

Question 25

Iodimetry

Answer 25

uses iodine quantifying iodine (directly reacting with the oxidizing analyte)

Question 26

Iodometry

Answer 26

produces iodine quantifying the analyte (from the reducing analyte, and iodine measured with thiosulfate)

Question 27

Determine the:
1. Moles of analyte
2. Volume of titrant to reach end point
3. pH at the start, halfway and at the endpoint for each of the titrations performed.

For the titration shown as follows: 50mL of a weak base (pKb = 5), 0.072M with 0.153M HCl.

Answer 27

3 × 10^-3 mol; 24 mL; 10.84, 8.82, 5.06

Question 28

When formic acid is 4.6% ionized in 0.105M of aqueous solution at room temperature, determine the ionization constant of the acid. If the solution containing 0.25N of 25mL acid is diluted to 202mL and titrated with 0.35 NaOH, calculate the pH value and the concentration of the hydrogen ion at the equivolume part.

Answer 28

2.2 × 10^-4; 8.06; 8.7 × 10^-9

Question 29

If aspirin is made using the raw materials salicylic acid and acetic anhydride with a yield of 75%, how many grams of aspirin will be produced

Answer 29

25