Question

g A sample that contains aluminum is reacted with sulfuric acid according to the equation given below. When the aluminum dissolved the total volume of gas collected over water at 25 °C is 0.722 L at a total pressure of 739 mm Hg. What mass of hydrogen gas is collected?

Answer 1

Answer: Mass of hydrogen gas is collected is 0.058 grams

Step-by-step explanation:

The balanced chemical reaction is :

`2Al+3H_2SO_4\rightarrow Al_2(SO_4)_3+3H_2`

According to the ideal gas equation:

PV=nRT

P = Pressure of the gas = 739 mm Hg = 0.97 atm (760mmHg= 1atm)

V= Volume of the gas = 0.722 L

n= moles of gas = ?

T= Temperature of the gas in kelvin =
`25^0C=(25+273)K=298K`

R= Gas constant =
`0.0821Latm/Kmol`

`0.97* 0.722=n* 0.0821* 298`

n=0.029

Mass of hydrogen =
`moles* {\text {Molar mass}}=0.029mol* 2g/mol=0.058g`

Mass of hydrogen gas is collected is 0.058 grams