Chapter 14.2, Problem 14.1.1PE

If the experiment in Figure 14.2 is run for 60 s, 0.16 mol A remain.
Which of the following statements is or are true?

1. After 60 s there are 0.84 mol B in the flask.
2. The decrease in the number of moles of A from t₁ = 0 s to t₂ = 20 s is greater than that from t₁ = 40 to t₂ = 60 s.
3. The average rate for the reaction from t₁ = 40 s to t₂ = 60 s is 7.0 × 10-3 M/s.

1. Only one of the statements is true.
2. Statements (i) and (ii) are true.
3. Statements (i) and (iii) are true.
4. Statements (ii) and (iii) are true.
5. All three statements are ture.