1
$Fe(S)+CuS{{O}_{۴}}(aq)\to FeS{{O}_{۴}}(aq)+Cu(s)$
✓
✗
2
$F{{e}_{۲}}{{O}_{۳}}(s)+۶Na(s)\to ۲Fe(s)+۳N{{a}_{۲}}O(s)$
✓
✗
3
$۲AgN{{O}_{۳}}(aq)+Zn(s)\to Zn{{(N{{O}_{۳}})}_{۲}}(aq)+۲Ag(s)$
✓
✗
4
$Zn{{(N{{O}_{۳}})}_{۲}}(aq)+Cu(s)\to Cu{{(N{{O}_{۳}})}_{۲}}(aq)+Zn(s)$
✓
✗