Calculate the work done against external atmospheric pressure when 1 g of water changes to

Question

1672cm3
of steam. Take the atmospheric pressure as
1.013×105Nm−2

Answer 1

you could use thus formula:
P=F/A

Answer 2

dW = p A dr
dW = p 4 pi r^2 dr
integrate
W = p (4/3) pi (r final^3 - r initial^3)
W = p (final volume - initial volume)