Missing question: "What is the spring's constant?"
Solution:
The object of mass m=6.89 kg exerts a force on the spring equal to its weight:

When the object is attached to the spring, the displacement of the spring with respect to its equilibrium position is

And by using Hook's law, we can find the constant of the spring:
Answer:
10. 36 g ZnCl2
Explanation:
Zn + 2HCl -> ZnCl2 + H2
0.076 mol Zn
1.37 mol HCl
3 mol H2
Limiting reactant: Zn
1 mol Zn -> 1 mol ZnCl2
0.076 mol Zn ->x x= 0.076 mol ZnCl2=10.36 g