what volume of gas at 40°C and 1.50 atm is necessary to react with 300 L of hydrogen gas measured at the same conditions?
2H2 (g) + O2 (g) --> 2H20 (g)
1.50 atm= 151.KPa
How would I solve this? Because I can't use: PV = nRT
I have pressure, temperature, r. There's no way I can find moles and volume. I need the moles.
So would I just do:
300L H2× 1 L O2 / 2 L H2
And I get 150L as the volume for Oxygen by using law of combining gases.
Your answer of 150 L is correct but I don't agree with anything else you said. What do you mean you have no way to obtain n = mols.
PV = nRT or n = PV/RT. For H2 you know P, V, R and T so you can calculate n for H2, convert to mols O2, then use pV = nRT and solve for V in L. You get the same 150 L but you went around the barn to get it. That's why someone thought of the law of combining gases. All of that "other stuff" cancels so that using the volume works the same (BUT MUCH QUICKER) as using mols. You leave out all that R, T, P stuff AS LONG AS YOU KNOW THE BEGINNING AND ENDING p AND T ARE THE SAME
To solve this problem, you need to use the ideal gas law, which is PV = nRT. However, in this case, you don't have the values for volume and moles directly. So, let's break down the steps to solve it:
1. Convert the given pressure of 1.50 atm to the unit of kilopascals (KPa): 1 atm = 101.3 KPa. Therefore, 1.50 atm = 151.95 KPa.
2. Find the number of moles of hydrogen gas using the ideal gas law. Rearrange the formula to solve for n (moles): n = PV / RT. Since you have the pressure (1.50 atm), temperature (40°C converted to Kelvin), and the ideal gas constant (R), you can substitute those values into the formula to find the moles of hydrogen gas.
3. Use the balanced chemical equation to determine the stoichiometry of the reaction. According to the balanced equation, the ratio of H2 to O2 is 2:1. This means that for every 2 moles of H2, you need 1 mole of O2 to react completely.
4. Convert the moles of hydrogen gas to moles of oxygen gas. Since the ratio of H2 to O2 is 2:1, you need half the number of moles of oxygen gas compared to hydrogen gas.
5. Determine the volume of oxygen gas using the ideal gas law. Now that you know the moles of oxygen gas, along with the given temperature and pressure, you can use the ideal gas law to calculate the volume of oxygen gas at those conditions.
Remember to convert the volume of oxygen gas to the units given in the question, which is liters (L).
So, to summarize, you need to calculate the moles of hydrogen gas using the ideal gas law, use the balanced chemical equation to find the moles of oxygen gas, and finally calculate the volume of oxygen gas using the ideal gas law once again to get the desired answer.