Question

Bài 17. Tính lượng oxi cần dùng để đốt cháy hết:
a) 4,65 gam Photpho b) 6,75 gam nhôm c) 3,36 lít hiđro

Answer 1

$a)4P+5O_2\xrightarrow{t^o}2P_2O_5$

$n_P=\dfrac{4,65}{31}=0,15(mol)$

$\Rightarrow n_{O_2}=0,1875(mol)$

$\Rightarrow m_{O_2}=0,1875.32=6(g)$

$b)4Al+3O_2\xrightarrow{t^o}2Al_2O_3$

$n_{Al}=\dfrac{6,75}{27}=0,25(mol)$

$\Rightarrow n_{O_2}=0,1875(mol)$

$\Rightarrow m_{O_2}=0,1875.32=6(g)$

$c)2H_2+O_2\xrightarrow{t^o}2H_2O$

$n_{H_2}=\dfrac{3,36}{22,4}=0,15(mol)$

$\Rightarrow n_{O_2}=0,075(mol)$

$\Rightarrow m_{O_2}=0,075.32=2,4(g)$