1In water, there is hydrogen bonding. If i add acetone to it. It might come in between those bonds and might weaken them to some extent. So, the volume should increase and will show +ve deviation. And will lead to greater vapour pressure.
the explanations given with the answers seems right to me as well. The explanation is "As the acetone is added it displaces molecules from the surface and hence vapour pressure is less"
Can someone help me where I went wrong.