Question

do now: mcqs – types of chemical reactions
name:
date:
class:

1. which type of reaction occurs when two or more substances combine to form one new substance?

a. decomposition b. combination
c. displacement d. double displacement

1. the reaction $caco_3 \

ightarrow cao + co_2$ is an example of a:
a. combination reaction
b. displacement reaction
c. decomposition reaction
d. neutralization reaction

1. in the reaction $zn + cuso_4 \

ightarrow znso_4 + cu$, zinc replaces copper. this is a:
a. combination reaction
b. double displacement reaction
c. decomposition reaction
d. displacement reaction

1. which reaction is a neutralization reaction?

a. $hcl + naoh \
ightarrow nacl + h_2o$
b. $2h_2 + o_2 \
ightarrow 2h_2o$
c. $caco_3 \
ightarrow cao + co_2$
d. $fe + cuso_4 \
ightarrow feso_4 + cu$

1. a precipitation reaction is best described as a reaction that:

a. produces heat
b. produces water only
c. forms an insoluble solid
d. breaks a compound apart

Explanation:

1. A reaction where multiple substances form one new substance is defined as a combination reaction.
2. The reaction $\text{CaCO}_3

ightarrow \text{CaO} + \text{CO}_2$ shows one compound breaking into two simpler substances, which is decomposition.

1. When one element replaces another in a compound, this is a displacement reaction.
2. Neutralization reactions occur between an acid (HCl) and a base (NaOH) to produce salt (NaCl) and water ($\text{H}_2\text{O}$).
3. A precipitation reaction is characterized by forming an insoluble solid product.

Answer:

1. B. Combination
2. C. Decomposition reaction
3. D. Displacement reaction
4. A. $\text{HCl} + \text{NaOH}

ightarrow \text{NaCl} + \text{H}_2\text{O}$

1. C. Forms an insoluble solid