Question

1.Н2+...→Н2S
...+CI2→PCI
...+...→Сa P

Answer 1

H2+S=H2S
P+Cl2=PCl5
Ca+P=CaP в третьем не уверен

Answer 2

H2+S=>H2S 2P+CL2=>2PCL Ca +P=>Ca P