Question

What will be the color of solution when copper oxide and dilute hydrochloric acid is mixed ?Write chemical equation for the reaction involved.

Answer 1

blue-green colour .
Copper oxide is a weak base, and it easily reacts with HCl forming soluble copper(II) chloride and water.CuO(s) + HCl(aq) = CuCl2(aq) + H2O(l)

Answer 2

Copper oxide is one of the most common oxide of copper metal with chemical formula CuO.

The reaction of copper oxide with dilute HCl forms $\bold{\mathrm{CuCl}_{2}\ \text{and}\ \mathrm{H}_{2} \mathrm{O}}$. Here $\mathrm{CuCl}_{2}$ forms a blue-green solution.

Hence when copper oxide and dilute hydrochloric acid is mixed it forms blue-green solution.  

The balance chemical equation can be written as:

$\bold{\mathrm{CuO}+2 \mathrm{HCl} \rightarrow \mathrm{CuCl}_{2}+\mathrm{H}_{2} \mathrm{O}}$

Overall color of solution changes to blue-green solution due to the reaction.