Question

Question #13431

Answer 1

A. `H_2+Br_2 to 2HBr`

Explanation:

A. `H_2+Br_2 to 2HBr`
This is a synthesis reaction, two reactants form a single product.

B. `Mg+H_2SO_4 to MgSO_4 + H_2`
This is clearly an reduction-oxidation reaction; `Mg` is oxidized and the `H^+` ions are reduced. This is since the former is more reactive than the latter in the activity series.

C. `NaCl to Na^+ + Cl^-`
This is merely a dissolution reaction, perhaps in an aqueous solution, such as water.

D. `2H_2O+2Na(s) to 2NaOH + H_2`
Another reduction-oxidation reaction, for the same reason as above!