Answer:
1,981.84 L of gas is formed from 1.40 lb of lithium hydride.
1,268.36 L of gas is formed from 1.40 lb of magnesium hydride.
Explanation:
Hydrogen gas from lithium hydride:
![LiH+H_2O\rightarrow LiOH+H_2](https://tex.z-dn.net/?f=LiH%2BH_2O%5Crightarrow%20LiOH%2BH_2)
Mass of LiH = 1.40 lb = 635.0288 g
1 lb = 453.592 g
Moles of LiH = ![\frac{635.0288 g}{8g/mol}=79.3786 mol](https://tex.z-dn.net/?f=%5Cfrac%7B635.0288%20g%7D%7B8g%2Fmol%7D%3D79.3786%20mol)
According to reaction,1 mole of LiH gives 1 mole of hydrogen gas.
Then 79.3786 mole of LiH will give :
of hydrogen gas.
Volume of hydrogen gas = V
Pressure of hydrogen gas , P= 750 Torr =0.987 atm
1 Torr = 0.00131579 atm
Temperature of the gas = T = 27°C = 300.15 K
Moles of gas = n = 79.3786 moles
![PV=nRT](https://tex.z-dn.net/?f=PV%3DnRT)
![V=\frac{nRT}{P}](https://tex.z-dn.net/?f=V%3D%5Cfrac%7BnRT%7D%7BP%7D)
![=\frac{79.3786 mol\times 0.0821 atm L/mol K\times 300.15 K}{0.987 atm}=1,981.84 L](https://tex.z-dn.net/?f=%3D%5Cfrac%7B79.3786%20mol%5Ctimes%200.0821%20atm%20L%2Fmol%20K%5Ctimes%20300.15%20K%7D%7B0.987%20atm%7D%3D1%2C981.84%20L)
Hydrogen gas from magnesium hydride:
![MgH_2+2H_2O\rightarrow Mg(OH)_2+2H_2](https://tex.z-dn.net/?f=MgH_2%2B2H_2O%5Crightarrow%20Mg%28OH%29_2%2B2H_2)
Mass of
= 1.40 lb = 635.0288 g
1 lb = 453.592 g
Moles of ![MgH_2=\frac{635.0288 g}{25 g/mol}=25.4011 mol](https://tex.z-dn.net/?f=MgH_2%3D%5Cfrac%7B635.0288%20g%7D%7B25%20g%2Fmol%7D%3D25.4011%20mol)
According to reaction,1 mole of
gives 2 mole of hydrogen gas.
of hydrogen gas.
Volume of hydrogen gas = V
Pressure of hydrogen gas , P= 750 Torr =0.987 atm
1 Torr = 0.00131579 atm
Temperature of the gas = T = 27°C = 300.15 K
Moles of gas = n = 50.8023 moles
![PV=nRT](https://tex.z-dn.net/?f=PV%3DnRT)
![V=\frac{nRT}{P}](https://tex.z-dn.net/?f=V%3D%5Cfrac%7BnRT%7D%7BP%7D)
![=\frac{50.8023 mol\times 0.0821 atm L/mol K\times 300.15 K}{0.987 atm}=1,268.36 L](https://tex.z-dn.net/?f=%3D%5Cfrac%7B50.8023%20mol%5Ctimes%200.0821%20atm%20L%2Fmol%20K%5Ctimes%20300.15%20K%7D%7B0.987%20atm%7D%3D1%2C268.36%20L)