Question

Action of CH3-MgBr on .....a} H-COH b}CH3-COH. c} CH3COCH​

Answer 1

wen the grignard adds to carbonyl/carbon dioxide, u get the anion formed, e.g. C2H5O-. so u need to add acid to protonate the O-, to get OH to make the alcohol.

when u add water or acid to a grignard, i think u get the alkane

e.g.

CH3MgBr+H2O gives CH4+MgBrOH

i.e. the water protonates the grignard. 

so i guess u add acid to neutralise the OH- generated?