How is dry ice different from ordinary ice?

Can someone me with questions 15 to 17 plz.

Each of the following reactions is allowed to come to equilibrium and then the volume is changed as indicated. predict the effect (shift right, shift left, or no effect) of the indicated volume change. drag the appropriate items to their respective bins. co(g) + h2o(g) < => co2(g) + h2(g) (volume is decreased) pcl3(g) + cl2(g) < => pcl5(g) (volume is increased) caco3(s)< => cao(s) + co2(g) (volume is increased)

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?