# Organic reaction of dry ice and Grignard reagent

Which of the following product is formed in the reaction $\ce{CH3MgBr}$ in DryIce/acid?
A) $\ce{CH3COOH}$
B) $\ce{CH4}$
C) $\ce{CH3OH}$
D) $\ce{CH3CH2CHO}$

My answer is A, since dry ice is $\ce{CO2}$ and it has one carbon atom and reactant has one carbon, so in all the product should have two carbon atoms, which is option A.

Am I correct?

You are correct. Grignard reagents $\ce{RMgX}$ (where $\ce{R}$ stands for some hydrocarbon group and $\ce{X}$ is a halogen, usually $\ce{Cl}$, $\ce{Br}$, or $\ce{I}$) react with carbon dioxide to produce carboxylic acids after acidic workup:
$$\ce{RMgX ->[1)\ \ce{ CO2}][2)\ \ce{ H3O+}] RCO2H}$$
$$\ce{RMgX + CO2 -> RCO2- MgX+}$$ $$\ce{RCO2- + H3O+ -> RCO2H + H2O}$$