Question

Carbonic acid (H2CO3) forms when carbon dioxide (CO2) dissolves in water according to this equation:

CO2 + H2O→H2CO3

How many moles of CO2 must dissolve in an excess of water to produce 2 moles of H2CO3?

Responses

1 mol

1 mol

2 mol

2 mol

3 mol

3 mol

4 mol

4 mol

Answer 1

2 mol

From the equation CO2 + H2O → H2CO3, the molar ratio CO2:H2CO3 is 1:1, so to make 2 moles of H2CO3 you need 2 moles of CO2.