Multiple choice and short answer chemistry questions covering nomenclature, reactions, oxidation states, molecular geometry, and acid-base properties.

$$x + 2(-1) = 0$$ $$x - 2 = 0$$ $$x = +2$$

B) +2

4- The shape of ammonium is:
C) tetrahedral

5- The most stable specie in an acidic environment is:
A) $\text{SO}_4^{2-}$

6- In a catalytic converter, the conversion of nitrogen oxides ($\text{NO}_x$) into nitrogen gas ($\text{N}_2$) and oxygen gas ($\text{O}_2$) is a process of:
B) Reduction

7- Sulfur is a member of group 16 which is also called as:
C) Chalcogens

8- A reddish brown gas, paramagnetic and react with water to form $\text{HNO}_3$ and $\text{HNO}_2$:
C) $\text{NO}_2$

9- Sulfur displays a range of oxidation states principally from:
C) -2 to +6

SHORT QUESTIONS

1. Why is ammonia weak base? Ammonia ($\text{NH}_3$) is a weak base because it only partially ionizes in water. It accepts a proton from water to form ammonium ions ($\text{NH}_4^+$) and hydroxide ions ($\text{OH}^-$), but the equilibrium lies predominantly towards the reactants, meaning only a small concentration of hydroxide ions is produced.