Khối lượng gas là $m(gam)$

`->`$m_{C_4H_{10}}=0.994m(gam);m_{C_5H_{12}}=0.006m(gam)$

`=>`$n_{C_4H_{10}}=\dfrac{0.994m}{58}(mol);n_{C_5H_{12}}=\dfrac{0.006m}{72}(mol)$

`->`$Q=\dfrac{0.994m}{58} \times 2654+\dfrac{0.006m}{72} \times 3600(kJ)$

$2(L)=2000(L)$ ứng với $2000(gam)$ nước.

$q=mC \delta T=2000 \times 4.16 \times (100-20)=665.6(kJ)$

Có: $Q=q$

`<=>`$\dfrac{0.994m}{58} \times 2654+\dfrac{0.006m}{72} \times 3600=665.6$

`=>`$m≈14.53781(gam)$