Question

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

dilute H2SO4 at a pressure of P=1.00 bar and
temperature of 298K. What is the reaction thatoccures? Calculate w
for the process.

Answer 1

Answer: Work done for the process is -390 J

Step-by-step 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}=(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* 8.314J/mol.K* 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