Question

multiple choice 2 points
identify the spectator ions in the reaction.
a. nh4+ & cro4
b. cro4 & ag+
c. no3 & nh4+
d. ag+ & no3
a
b
c
d
7
multiple choice 2 points
which substance is a hydrate?
a. cacl2 x 2h2o
b. ch4
c. h2o
d. mg(oh)2
a
b
c
d

Explanation:

A hydrate is a compound that contains water molecules chemically bound in its structure. The general formula for a hydrate is \( \text{compound}\cdot x\text{H}_2\text{O} \).

• Option A: \( \text{CaCl}_2\times2\text{H}_2\text{O} \) (or \( \text{CaCl}_2\cdot2\text{H}_2\text{O} \)) is a hydrate. It is calcium chloride dihydrate.
• Option B: \( \text{CH}_4 \) (methane) is a hydrocarbon and does not contain water molecules in its structure.
• Option C: \( \text{H}_2\text{O} \) is water itself, not a hydrate (a hydrate is a compound with water of crystallization attached to another compound).
• Option D: \( \text{Mg(OH)}_2 \) (magnesium hydroxide) is a base and does not have water molecules chemically bound in the way a hydrate does.

Answer:

A. \( \text{CaCl}_2\times2\text{H}_2\text{O} \)