Thermodynamics - Please help me to calculate the final gas pressure.

[SAFiiNA]

Homework Statement

A fixed mass of gas at a constant pressure of 1 x 10⁵ N/m² (pascal) expands to twice its volume at constant temperature of 27°C. The volume is then kept constant, and the gas is heated to 87°C. Calculate the final gas pressure.

Homework Equations

I think this is the equation PV/nT=R that I need for this question.

The Attempt at a Solution

I am clueless to be honest. I am only given pressure and temperature to work this out. Can anyone please help me?

 

[Astronuc]

Homework Statement

A fixed mass of gas at a constant pressure of 1 x 10⁵ N/m² (pascal) expands to twice its volume at constant temperature of 27°C. The volume is then kept constant, and the gas is heated to 87°C. Calculate the final gas pressure.

Homework Equations

I think this is the equation PV/nT=R that I need for this question.

The Attempt at a Solution

I am clueless to be honest. I am only given pressure and temperature to work this out. Can anyone please help me?

Well the system is closed to the number of atoms (or moles) is fixed. Given three variables P, V, T, if one is fixed, then there is a linear relationship between the other two. For example if T is fixed (constant), then by the ideal gas law, PV = some constant. So if V doubles, what happen to P?

 

[th4450]

Then, volume is constant, apply pressure law.
\frac{p_{1}}{T_{1}} = \frac{p_{2}}{T_{2}}
*Remember to change the temperature from ^oC to K

 

[SAFiiNA]

Thank you guys for your help. I worked it out and I have got the answer 12 x 10⁴..is this correct?

 

[Astronuc]

Thank you guys for your help. I worked it out and I have got the answer 12 x 10⁴..is this correct?

It would help if one were to show the steps (equations) and provide units with the numbers.

 

[SAFiiNA]

It would help if one were to show the steps (equations) and provide units with the numbers.

I worked it out using the formula mentioned above on this thread. So P¹ = 1x10⁵ N/m², T¹ = 27°C + 273 = 300K, P² = ? & T² = 87°C + 273 = 360K.

1 x 10⁵N/m² / 300 = P² / 360
1x10⁵ x 360 = P² x 300
1x10⁵ x 360 / 300 = P²
P² = 12 x 10⁴ N/m²

 

[th4450]

I worked it out using the formula mentioned above on this thread. So P¹ = 1x10⁵ N/m², T¹ = 27°C + 273 = 300K, P² = ? & T² = 87°C + 273 = 360K.

1 x 10⁵N/m² / 300 = P² / 360
1x10⁵ x 360 = P² x 300
1x10⁵ x 360 / 300 = P²
P² = 12 x 10⁴ N/m²

p₁ is not correct because "a constant pressure of 1 x 10⁵ N/m² (pascal) expands to twice its volume at constant temperature of 27°C"

 

[SAFiiNA]

th4450 thank you so much for your help. I have done it right now and got it checked by my teacher. Thanks :)