Question

How many liters of HCl gas, measured at 30.0 °C and 745 torr, are required to prepare 1.25 L of a 3.20-M solution of hydrochloric acid?

Answer 1

Answer:

102 L

Explanation:

Data of the solution

• Concentration: 3.20 M

• Volume: 1.25 L

The moles of HCl in the solution are:

1.25 L × 3.20 mol/L = 4.00 mol

The gas must contain 4.00 moles of HCl

Data of the gas

• Temperature (T): 30.0 °C + 273.15 = 303.2 K

• Pressure (P): 0.980 atm

745 torr × (1 atm/760 torr) = 0.980 atm

• Moles (n): 4.00 mol

We can the volume (V) of HCl gas using the ideal gas equation.

P × V = n × R × T

V = n × R × T/P

V = 4.00 mol × (0.08206 atm.L/mol.K) × 303.2 K/ 0.980 atm

V = 102 L