Chemistry Test 220

Result

Chemistry Test 220

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Weekly Quiz Competition

Question 1
4 / -1

A 19^th century iron bridge is protected from corrosion by connecting it to a block of metal (sacrificial anode), which is replaced annually. The corrosion of iron, represented by the chemical equation:

Which of the following metals is best suited as sacrificial anode:

A

B

C

D
Question 2
4 / -1

The cell potential for the following electrochemical system at 25°C is:

Al(s) | Al³⁺ (0.01 M) || Fe²⁺ (0.1 M) | Fe (s)

Given: Standard reduction potential of Al³⁺ + 3e^– → Al is –1.66 V at 25°C

Standard reduction potential of Fe²⁺ + 2e^– → Fe is –0.44 V at 25°C

A
1.23 V

B
1.21 V

C
1.22 V

D
–2.10 V

Solution
Question 3
4 / -1

The species present in solution when CO₂ dissolved in water, are

A

B

C

D

Solution

H₂CO₃ is formed by dissolution of CO₂ into water. This dissociates into H+ and HCO^3-. This is the first dissociation of H₂CO₃. Since HCO^3- has another H, it again dissociates to H⁺ and CO₃^2-. H+ obtained attacks the lone pair of H₂O to form H₃O⁺. So H₃O⁺, HCO^3-, CO₃^2-, H₂CO₃ are present in water when CO₂ is dissolved in water.
Question 4
4 / -1

The reduction potential of an element A is 1.71 V. What can be concluded from this?

A
A will lose electrons easily.

B
A will undergo reduction easily.

C
A will undergo oxidation easily.

D
A will be a good reducing agent.

Solution

The standard reduction potential is the tendency for a chemical species to be reduced, and is measured in volts at standard conditions.

The more positive the potential is the more likely it will be reduced. Hence, A will undergo reduction easily.
Question 5
4 / -1

Aerated water contains CO₂ dissolved in water

Variation of solubility (s) with pressure (p) is shown by

A

B

C

D

Solution

Pressure increase solubility also increase in accordance with the Henry's law and option B is the closest to this. Hence B is correct.
Question 6
4 / -1

Which of the following involves a redox reaction?

A
Reaction of H₂SO₄ with NaOH

B
Production of ozone from oxygen in the atmosphere by lightning

C
Production of nitrogen oxides from nitrogen and oxygen in the atmosphere by lightning

D
Evaporation of water

Solution
Question 7
4 / -1

The equilibrium constant of the reaction:

E° = 0.46 V at 298 K is

A
2.0 × 10¹⁰

B
4.0 × 10¹⁰

C
4.0 × 10¹⁵

D
2.4 × 10¹⁰

Solution
Question 8
4 / -1

A
a

B
b

C
c

D
None of the above

Solution
Question 9
4 / -1

Solubility of MX₂-type eletrolytes is 0.5 × 10^–4 mole/lit, then find out K_spof electrolytes

A
5 × 10^–12

B
25 × 10^–10

C
1 × 10^–13

D
5 × 10^–13

Solution
Question 10
4 / -1

A
–2

B
-1

C
1

D
2