2002 Chevy Impala Shakes

My car shakes when acceleratinbg down the road. When I release the gas it stops and as soon as I press the gas agin it starts to shake on the front end. Usually happens when we travel out of town, in town no problem. After we have been driving, we get into town slow down smooths out and when I give it a little gas it really shakes. I've put new tires on the front had them balanced. Have heard that it might be my motor mounts? Need an expert opinion