1. Which of the following is a combination reaction?

a. 2SO2 + O2-> 2SO3

b. Zn + Cu (NO3) 2->Zn (NO3) 2 + Cu

c. 2H2O2-> 2H2O+O2

d. AgNO3 + NaCl → AgCl+NaNO3

The answer to your question is: letter A

Explanation:

A combination reaction is when there are two reactants that gives only one product.

a. 2SO2 + O2-> 2SO3 This is a combination reaction,

2 reactants gives one product.

b. Zn + Cu (NO3) 2->Zn (NO3) 2 + Cu This is not a combination reaction,

it's a single replacement reaction.

c. 2H2O2-> 2H2O+O2 This is a decomposition reaction

d. AgNO3 + NaCl → AgCl+NaNO3 THis is a double replacement reaction.