Question

A pellet of Zn of mass 10.0g is dropped into a flaskcontaining

Answer 1

Answer: Work done for the process is -390 J

Explanation:

The chemical equation for the reaction of zinc metal with sulfuric acid follows:

$Zn+H_2SO_4\rightarrow ZnSO_4+H_2$

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of zinc = 10.0 g

Molar mass of zinc = 65.38 g/mol

Putting values in above equation, we get:

$\text{Moles of zinc}=\frac{10.0g}{65.38g/mol}=0.153mol$

The equation given by ideal gas follows:

$P\Delta V=nRT$

where, P = pressure of the gas

$\Delta V$ = Change in volume of the gas

T = Temperature of the gas = 298 K

R = Gas constant = 8.314 J/mol.K

n = number of moles of gas = 0.153 mol

Putting values in above equation, we get:

$P\Delta V=0.153mol\times 8.314J/mol.K\times 298K\\\\P\Delta V=397J$

To calculate the work done, we use the equation:

$\text{Work done}=-P\Delta V\\\\W=-390J$

Hence, work done for the process is -390 J