A mixture of CO and `CO_2` gas is there. How would you convert the whole mixture to
Carbon Dioxide

Explanation

Conversion to `CO_2`: when the mixture of CO and `CO_2` is passed over black cupric oxide (CuO) heated to `300^@C`, CO is oxidised to `CO_2` `CO_2` remains unchanged. In this way the whole mixture is converted to `CO_2`
`CuO+COtoCu+CO_2`