Question

please I need help
The action of heat on blue crystalline solid L gives reddish brown gas M , a gas relights a glowing splint and leaves behind a black residue .When N which has rotten egg smell is passed through a solution of L a black precipitate is formed ...IDENTIFY L,M,N

Answer 1

cu(no3) 2-:cuo+no2+o2
M-no2
Black residue - cuo
H2s+cuo-:cu2s+h20
L-cu(no3) 2,m-no2, n-h2s