HSC 2020 Chemistry Exam Answers - Questions - 16 - 18

This video covers the answer to all multiple choice questions 16 - 18 of the 2020 NSW HSC Chemistry Exam.

0:00 Intro
0:06 Q16 - Compounds X, Y and Z are in equilibrium. The diagram shows the effects of temperature and pressure on the equilibrium yield of compound Z. Which equation would be consistent with this data?
3:51 Q17 - The following apparatus was set up in a temperature-controlled laboratory. Excess solid sodium hydroxide is added to the beaker. Which row of the table correctly identifies the change in the CuSO4(s) mass and the colour of the solution after several days?
8:30 Q18 - An aqueous solution of sodium hydrogen carbonate has a pH greater than 7. Which statement best explains this observation?

Q16 Compounds X, Y and Z are in equilibrium. The diagram shows the effects of temperature and pressure on the equilibrium yield of compound Z.
Which equation would be consistent with this data?
A. X(g) + 3Y(g) -- 2Z(g) DH gt 0
B. X(g) + 3Y(g) -- 2Z(g) DH ls 0
C. 2X(g) -- 2Y(g) + Z(g) DH gt 0
D. 2X(g) -- 2Y(g) + Z(g) DH ls 0

Q17 The following apparatus was set up in a temperature-controlled laboratory. Excess solid sodium hydroxide is added to the beaker. Which row of the table correctly identifies the change in the CuSO4(s) mass and the colour of the solution after several days?

Q18 An aqueous solution of sodium hydrogen carbonate has a pH greater than 7.
Which statement best explains this observation?
A. H2O(l) is a stronger acid than HCO3−(aq).
B. HCO3−(aq) is a weaker acid than H2CO3(aq).
C. Na+(aq) reacts with water to produce the strong base NaOH(aq).
D. The conjugate acid of HCO3−(aq) is a stronger acid than H2O(l).