Calculate the work done when 60.0 g of tin dissolves in excess acid at 1.00 atm and 20°C. Assume ideal gas behavior.

1 answer

The work done is different from the heat released, and can be calculated as the pressure multiplied by the volume change. The volume change is the result of the liberation of H2 gas by the reaction.

60.0 g of Sn is 0.505 moles.

In a reaction between Sn and an acid, two possible products can result,corresponding to a stannic or stannous salt. If a stannic product forms, as in the reaction
Sn + 4 HCl -> 2 H2 + SnCl4,
then 1.01 moles of H2 will be formed. The gas volume created at these NTP conditions will be
delta V = 24.1 liters = 24.1*10^-3 m^3.

The work done is P*deltaV Joules, with P =1.013*10^5 Pascals.