Question

question 3 of 10
which of the following is an example of a synthesis reaction?

a. $\ce{h_{2} + br_{2} -> 2hbr}$

b. $\ce{nacl -> na^{+} + cl^{-}}$

c. $\ce{2h_{2}o + 2na -> 2naoh + h_{2}}$

d. $\ce{mg + h_{2}so_{4} -> mgso_{4} + h_{2}}$

Explanation:

A synthesis reaction is when two or more substances combine to form a single product. Let's analyze each option:

• Option A: \( \ce{H_2 + Br_2

ightarrow 2HBr} \) shows two reactants (\( \ce{H_2} \) and \( \ce{Br_2} \)) combining to form one product (\( \ce{HBr} \)), which fits a synthesis reaction.

• Option B: \( \ce{NaCl

ightarrow Na^+ + Cl^-} \) is a dissociation (ionization) of a compound into ions, not a synthesis.

• Option C: \( \ce{2H_2O + 2Na

ightarrow 2NaOH + H_2} \) is a single - replacement reaction (Na replaces H in \( \ce{H_2O} \)).

• Option D: \( \ce{Mg + H_2SO_4

ightarrow MgSO_4 + H_2} \) is also a single - replacement reaction (Mg replaces H in \( \ce{H_2SO_4} \)).

Answer:

A. \( \ce{H_2 + Br_2
ightarrow 2HBr} \)