Hydrogen gas (7.0 mL) is mixed with chlorine gas(4.0 mL) at a certain pressure and temperature. A
reaction between H2and Cl2 is initiated by UV light.
If pressure and temperature are kept constant, which gases and in which volumes will be found after the reaction is completed?
The reaction is as followed:
H2 + Cl2 ----> 2HCl
You can treat this as a limiting reagent problem, where Cl2 is the limiting reagent.
1 mole of Cl2=2 moles of HCl
or
1mL of Cl2= 2 mL of HCl
4.0mL of Cl2*(2 mL of HCl/Cl2)= 8mL of HCl (g)
For volume H2 unused at the end of the reaction.
4.0 mL Cl2 x (1 mol H2/1 mol Cl2) = 4.0 mL H2 used. Amount H2 left = 7.0-4.0 = 3.0 mL.
So you will have 3.0 mL H2, zero mL Cl2, and 4.0 mL HCl when the reaction is finished.
I didn't fully read this question; I was wondering what Dr.Bob222 did.
He is correct: 4.0mL of of Cl2 will be used meaning that there will be no Cl2 left at the end of the reaction, but 3.0mL of H2 gas will be left after the reaction is complete. However, I'm not sure where the 4.0mL of HCl produced comes from because I think that there will be 8.0mL of the acid will be produced at the end of the reaction.
To determine the volume of gases after the reaction is completed, we need to examine the stoichiometry of the reaction between hydrogen gas (H2) and chlorine gas (Cl2).
The balanced chemical equation for the reaction between H2 and Cl2 is as follows:
H2 + Cl2 → 2HCl
From the balanced equation, we can see that one mole of hydrogen gas reacts with one mole of chlorine gas to produce two moles of hydrogen chloride gas.
Since we know the initial volumes of hydrogen gas (7.0 mL) and chlorine gas (4.0 mL), we need to convert these volumes into moles.
To do this, we need to know the molar volume of gases at the given pressure and temperature. Without this information, we cannot directly convert volumes into moles.
However, if we assume that the gases behave ideally (following the ideal gas law) and if the pressure and temperature are kept constant, the ratio of the volumes of the reacting gases is the same as the ratio of their stoichiometric coefficients.
In this case, the stoichiometric coefficients from the balanced equation tell us that the reactant ratio is 1:1, meaning that one volume of hydrogen gas reacts with one volume of chlorine gas to produce two volumes of hydrogen chloride gas.
Therefore, if the reaction goes to completion, we would expect the volume of hydrogen gas (H2) to be completely consumed, resulting in a volume of 0 mL. Similarly, the volume of chlorine gas (Cl2) would also be consumed completely, resulting in a volume of 0 mL.
The newly formed hydrogen chloride gas (HCl) would have a volume of 2 times the initial volume of either hydrogen gas or chlorine gas, which would be 2 * (7.0 mL) = 14.0 mL.
So, after the reaction is completed, the gases and their volumes would be:
- Hydrogen gas (H2): 0 mL
- Chlorine gas (Cl2): 0 mL
- Hydrogen chloride gas (HCl): 14.0 mL