Question

a sample of 0.400 moles of nitrogen occupies 0.800L. under the same conditions what number of moles occupies 1.200L

Answer 1

We know that PV = nRT

Where

T = Temperature ;P = pressure ; n = No . of moles ;R = gas constant ; V= Volume of the gas

As the gas remains the same , n will constant , P & T are kept constant

So V is proportional to n

Thereby V / V' = n/ n'

Where

V = initial volume = 0.800 L

V' = final volume = 1.200 L

n = initial moles = 0.400 moles

n' = final moles = ?

Plug the values we get

n' = (n x V')/ V

   = ( 0.400x 1.200) / 0.800

  = 0.6 moles

Therefore the required number of moles is 0.60 moles