Solving a Take Home Quiz: Determining Gas Density

In summary, the conversation is discussing a problem on a take-home quiz involving calculating the new density of helium gas when the temperature is raised to 100°C while keeping the pressure constant. The equation P1V1/T1 = P2V2/T2 is provided, but the issue is that the density formula requires either mass or volume, which are not given. The solution is to find the proportional increase in volume and use the fact that the mass of the gas does not change.
  • #1
Cheapo2004
9
0
Heres a problem on a take home quiz I am doing, but i can't figure out how to get past the first step?!

The density of helium gas at 0°C is 0.179 kg/m^3. The temperature is then raised to 100°C, but the pressure is kept constant. Assuming that Helium is an ideal gas, calculate the new density of the gas.

Heres the equations i have:
P1V1 / T1 = P2V2 / T2

In order to work this equation i need volume, but i have a density, here's the equation i think i need:

roe = m / V
(density = mass / volume)

How do i work this if i don't have mass or volume?!
 
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  • #2
Cheapo2004 said:
Heres a problem on a take home quiz I am doing, but i can't figure out how to get past the first step?!

The density of helium gas at 0°C is 0.179 kg/m^3. The temperature is then raised to 100°C, but the pressure is kept constant. Assuming that Helium is an ideal gas, calculate the new density of the gas.

Heres the equations i have:
P1V1 / T1 = P2V2 / T2

In order to work this equation i need volume, but i have a density, here's the equation i think i need:

roe = m / V
(density = mass / volume)

How do i work this if i don't have mass or volume?!
You have to find the proportional increase in volume: V2/V1. You know P1 and P2 (they are the same. You know T1 and T2. All you have to find is V2/V1.

AM
 
  • #3
You know the mass of the gas doesn't change. Try putting the density formula into the equation, you will find that they cancel out.
 

What is the formula for determining gas density?

The formula for determining gas density is density = mass/volume. This means that the density of a gas is equal to its mass divided by its volume.

What are the units for gas density?

The units for gas density are typically grams per liter (g/L) or kilograms per cubic meter (kg/m^3). However, the specific units may vary depending on the units used for mass and volume in the formula.

How do you measure the mass of a gas for determining gas density?

The mass of a gas can be measured using a balance scale or by using the ideal gas law (PV = nRT) to calculate the number of moles of gas present and then multiplying by the molar mass of the gas.

What is the importance of determining gas density?

Determining gas density is important in many scientific and practical applications. It can help us understand the behavior of gases, predict their movement and interactions, and determine their suitability for different uses such as fuel, air quality, or packaging.

How can I check the accuracy of my gas density calculation?

To check the accuracy of your gas density calculation, you can compare it to known values or use multiple methods to calculate the density and compare the results. It is also important to double check your calculations and ensure that you are using the correct units and formula.

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