Question

while heating mass change only occur is physical or chemical change

Answer 1

it is a physical change because after the reaction and before the reaction all the masses  are changes or by heating and applying pressure we can also find change in the mass .

for example the mass of the copper is 4 gm then after the reaction we get it is 2 gm but from the electrolysis process we can get again 4 gm copper in the electrolysis of the copper suplahte