Question

unit 6 test multiple choice
part 1: classify each type of reaction as single replacement, double replacement, decomposition, synthesis, or combustion.

1. \\( 1\\ al_2(so_4)_3 + 6 k(oh) \

ightarrow 2al(oh)_3 + 3k_2(so_4) \\)
a. single replacement
b. double replacement
c. synthesis/combination
d. decomposition
e. combustion

1. \\( 4fe + 3o_2 \

ightarrow 2fe_2o_3 \\)
a. single replacement
b. double replacement
c. synthesis/combination
d. decomposition
e. combustion

1. \\( 1 naoh + 1hcl \

ightarrow 1 nacl + 1 h_2o \\)
a. single replacement
b. double replacement
c. synthesis/combination
d. decomposition
e. combustion

1. \\( 1mg + 2ag(no_3) \

ightarrow 1mg(no_3)_2 + 2ag \\)
a. single replacement
b. double replacement
c. synthesis/combination
d. decomposition
e. combustion

1. \\( 1 fe_2o_3 + 3c \

ightarrow 2fe + 3co \\)
a. single replacement
b. double replacement
c. synthesis/combination
d. decomposition
e. combustion

1. \\( 1c_4h_8 + 6o_2 \

ightarrow 4co_2 + 4h_2o \\)
a. single replacement
b. double replacement
c. synthesis/combination
d. decomposition
e. combustion

1. \\( 1znco_3 \

ightarrow 1co_2 + 1 zno \\)
a. single replacement
b. double replacement
c. synthesis/combination
d. decomposition
e. combustion
part 2: physical and chemical property and change questions.

1. physical properties are:

a. those that a substance displays only through changing its composition.
b. those that cause atoms and molecules to change.
c. those that a substance displays without changing its composition.
d. identical for all solid matter.

1. all of the following are physical properties except

a. taste.
b. color.
c. flammability (ability to burn).
d. density.

1. which of the following is an example of a chemical property?

a. the paint color on a new red corvette
b. the odor of spearmint gum
c. the melting and boiling point of water
d. the tarnishing of a copper statue

1. if you hold a solid piece of pure gallium metal in your hand, your body heat will melt the gallium into its liquid form. this illustrates which of the following?

a. distillation
b. physical change
c. chemical change
d. chemical property

1. which of the following is not evidence of a chemical change?

a. color change
b. formation of a precipitate
c. evolution or absorption of heat
d. dissolving

Explanation:

Part 1: Reaction Classification

Question 1

Step 1: Identify reaction type.

In the reaction $\ce{Al2(SO4)3 + 6KOH -> 2Al(OH)3 + 3K2(SO4)}$, the cations ($\ce{Al^{3+}}$ and $\ce{K^+}$) and anions ($\ce{SO4^{2-}}$ and $\ce{OH^-}$) swap partners. This matches double replacement (ions exchange between compounds).

Step 1: Identify reaction type.

The reaction $\ce{4Fe + 3O2 -> 2Fe2O3}$ combines two substances (Fe and $\ce{O2}$) into one ($\ce{Fe2O3}$), which is synthesis/combination.

Step 1: Identify reaction type.

In $\ce{NaOH + HCl -> NaCl + H2O}$, $\ce{Na^+}$ swaps with $\ce{H^+}$, and $\ce{OH^-}$ swaps with $\ce{Cl^-}$. This is double replacement (acid - base neutralization, a type of double replacement).

Answer:

b. Double Replacement

Question 2