Question

Sodium reacts with chlorine gas according to the reaction What volume of Cl2 gas, measured at 867 torr and 55.0 °C, is required to form 42.0 g NaCl (58.44 g/mol)

Answer 1

2Na + Cl₂ 2NaCl

Number of moles of NaCl , n = mass/molar mass

                                          = 42.0 g / 58.44 (g/mol)

                                          = 0.719 moles

According to the above balanced equation ,

2 moles of NaCl formed from 1 mole of Cl₂

0.719 moles of NaCl formed from M mole of Cl₂

M = ( 1x0.719) /2

    = 0.359 moles

Calculation of volume of chlorine gas :

We know that PV = nRT

Where

T = Temperature = 55.0 oC = 55.0+273 = 328 K

P = pressure = 867 torr = 867/760 atm = 1.140 atm

n = No . of moles = 0.359 mol

R = gas constant = 0.0821 L atm / mol - K

V= Volume of the gas = ?

Plug the values we get

V = nRT / P

   = ( 0.359x0.0821x328) / 1.140

   = 8.48 L

Therefore the volume of chlorine gas is 8.48 L