A brown coloured metal x when heated gives a black colour metal oxide y. the black colour compound y reacts with hcl to give z. find x,y,z

A brown coloured metal x when heated gives a black colour metal oxide

1.	A brown coloured metal x when heated gives a black colour metal oxide y. the black colour compound y reacts with hcl to give z. find x,y,z
Answer» The SHINY brown COLORED element x is copper. When copper metal is heated in air, it forms a black colour compound copper oxide. So, the black COLOURED compound is copper oxide (CuO). 2Cu+O2-----heat-----2CuO when it REACTS with HCl it gives CuO+2HCl--------CUCL2+ H2O therefore z is CuCl2