Bài 3:
4P + 5O2 \(\underrightarrow{t^o}\) 2P2O5
a, Theo ĐLBTKL, ta có:
mP + m\(O_2\) = m\(P_2O_5\)
b, \(\Rightarrow m_{O_2}=24,2-3,1=21,1g\)
Bài 4:
Fe + S \(\underrightarrow{t^o}\) FeS
a, Theo ĐLBTKL, ta có:
mFe + mS = mFeS
b, \(\Rightarrow m_{FeS}=5,6+4=9,6g\)