2017 U3A2 Exam Questions

Answer the question in the image

• A

• B

• C

• D

Answer explanation

96% accuracy by students in 2017 - easy question

Answer the question in the image

• A

• B

• C

• D

Answer explanation

21% accuracy by students in 2017 (Very Hard Question)
From the ‘rates’ perspective the temperature increase will cause the rates of both the forward and reverse reactions to increase since it increases the proportion of collisions with energy greater than the activation energy. From the ‘extent of reaction’ perspective, since the forward reaction is exothermic, the temperature increase will favour the endothermic reverse reaction, so there will be less NH3 present at the higher temperature and the [NH3] will be lower. The rate of the forward reaction will continue to increase as the reaction returns to equilibrium since the reactant concentrations increase during that adjustment. The popularity of option C suggests that most students focused on the way the system compensated for the temperature increase and did not pay due atten

Answer the question in the image

• A

• B

• C

• D

Answer explanation

56% accuracy by students in 2017 (Average in difficult)
Recharging involves the conversion of electrical energy to chemical energy. 2PbSO₄(s) + 2H₂O(l) → Pb(s) + PbO₂(s) + 4H⁺ (aq) + SO₄ ^2– (aq) Since [H⁺ ] increases, the pH decreases.

Answer the question in the image

• A

• B

• C

• D

Answer explanation

80% accuracy by students in 2017 (easy in difficult)
Recharging involves the conversion of electrical energy to chemical energy. 2PbSO₄(s) + 2H₂O(l) → Pb(s) + PbO₂(s) + 4H⁺ (aq) + SO₄ ^2– (aq) Since [H⁺ ] increases, the pH decreases.

Answer the question in the image

• A

• B

• C

• D

Answer explanation

35% accuracy by students in 2017 (hard in difficult)