Avogadro's law states that volume is proportional to moles of gas.  Temperature and pressure are fixed.  Boyle law states that volume of gas is inversely proportional to pressure.  Charles' law states that volume of gas is proportional to temperature.  

Recall the Ideal Gas Law:

Since the question is asking for volume, rearrange the equation to the following:

Also recall that for the Ideal Gas Law equation to work, the temperature must be given in degrees Kelvin, and we will also need the number of moles of gas.

Start by converting the mass of gas into moles:

Don't round the values just yet.

Next, convert the temperature into degrees Kelvin.

Now, plug in all the given values into the equation to solve for volume:

The answer should have  significant figures.

The volume is .

Recall the Ideal Gas Law:

Because we want the amount of gas in the cylinder, we must find the number of moles of oxygen present first. Rearrange the Ideal Gas Law to solve for the number of moles of oxygen.

Plug in the given information to solve for the number of moles.

Now, convert the number of moles to the number of grams by using the molar mass of oxygen gas.

Make sure that your answer has  significant figures.

Use the ideal gas equation

Rearrange to solve for the volume

An ideal gas with a pressure of  is is compressed to  of its original volume, what is the new pressure?

Use Boyle’s law:

You want to solve for the new pressure so isolate :

It compresses to  its original volume so, 

Plug in everything we know:

Cancel  from the numerator and denominator

Use Boyle’s law:

You want to solve for the new pressure so isolate :

It expands to  its original volume, so 

Plug in everything we know:

Cancel  from both the numerator and denominator

Use the combined gas law:

Solve for  since that is the new volume for which we need to solve:

Since we have the total pressure and the pressures of helium and nitrogen, we can find the pressure of neon in this container.

Next, convert this pressure into atmospheres.

Now, recall the Ideal Gas Law:

Rearrange the equation to solve for moles of gas:

Using the pressure of neon, find the moles of neon that is present in the container.

Finally, convert the moles of neon into grams of neon using the molar mass.

Make sure your answer has  significant digits.

For this question, we're told that a chemical reaction is producing hydrogen gas. In doing so, the gas is displacing a certain amount of water vapor. We're asked to determine the number of moles of gas produced in this process.

The amount of water displaced by the production of hydrogen gas will be the amount (volume) of hydrogen gas produced. To measure its pressure, we take the reading of the total pressure and then subtract from it the pressure of water vapor (since it contributes to the total pressure). Using this information, we can use the ideal gas equation to determine the number of moles of hydrogen gas.

Next, we can use the ideal gas equation to solve for our answer.

To start, first recognize that this is an ideal gas law problem

Rearranging the equation to solve for P gives us

To solve the problem, we now need to find the total number of moles in the gaseous mixture n_tot. To do this, convert the values for Ne and He to moles and add them together

Now that we have n_tot, plug known values into the ideal gas law equation. Remember to convert from Celsius to Kelvin!