Question

For an ideal gas, calculate the following quantities.

(a) The pressure of the gas if 0.135 mol occupies 207 mL at 25°C.

______atm

(b) The temperature (in kelvins) at which 0.0250 mol occupies 1.00 L at 0.563 atm. K (c) The number of moles in 4.50 L at -7°C and 715 torr. Remember 1atm = 760 torr.

_____mol

(d) The volume occupied by 4.72 10-3 mol at 40.°C and a pressure of 1.57 kPa. Remember 1 atm = 101.325 kPa

_______L

Answer 1

(a)

n= 0.135 mol

V= 0.207 L

T= 298.15 K

R= 0.082 atm L / mol K

PV=nRT

P= (0.135 mol x (0.082 L atm / mol K ) x 298.15 K ) / 0.207 L

= 15.94 atm

(b)

PV=nRT

T= 0.563 atm x 1 L / ( 0.0250 mol x 0.082 L atm / mol K)

= 274.63 K

(c)

PV=nRT

n= (715 torr / 760 tprr ) x 4.50 L / ( 0.082 L atm / mol K x (273.15 - 7))

= 0.194 mol

(d)

Pressure = 1.57 kPa

Pressure in atm = 1.57 kPa / 101.325 kPa = 0.0155 atm

R= 0.082 atm L / mol K

PV=nRT

V= (0.00472 mol x (0.082 L atm / mol K ) x 313.15 K ) / 0.0155 atm

= 7.82 L