C. Consider the reaction 2C3H6 + 9O2 6CO2 + 6H2O. If the rate at which C3H6 is reacting is 0.40 mol liter−1s−1, then the rate at which
1. O2 is reacting is 1.6 mol liter−1s−1
2. CO2 is being formed is 0.40 mol liter−1s−1
3. H2O is being formed is 0.80 mol liter−1s−1
4. CO2 is being formed is 1.2 mol liter−1s−1
5. H2O is being formed is 1.6 mol liter−1s−1
6. none of the previous answers is correct
My thoughts:
I'm really struggling on this one. All I have figured out thus far is that C3H6 is a second order reaction, but I don't know if that even matters. Do I try to find the k value and then use that for the other ones? Any help in the right direction would be great! Thanks
You can go to this site and determine the order. I don't believe second order is correct.
https://en.wikipedia.org/wiki/Reaction_rate_constant#Units
I would do this as if it were a stoichiometry problem.
Calculate the rate for each. For example, for #1 (O2), it is
0.4 x (9 mols O2/2 mols C3H8) = 1.8 so 1 is not the answer. Etc.
Yeah, I was wrong, and it is a zero order reaction. If I do it that way, I get 4 to be an answer. Why can you do this as a stoichiometry problem? I guess I thought the rate orders were separate from the stoichiometric coefficients?
To determine the rates of the other species in the reaction, you need to consider the stoichiometry of the reaction. From the balanced equation, you can see that the molar ratio between C3H6 and O2 is 2:9, meaning for every 2 moles of C3H6 reacting, 9 moles of O2 are reacting.
1. The rate at which O2 is reacting is directly proportional to the rate at which C3H6 is reacting. Since the rate of C3H6 is given as 0.40 mol L^−1 s^−1, and the molar ratio between C3H6 and O2 is 2:9, the rate at which O2 is reacting can be calculated as:
(0.40 mol L^−1 s^−1) × (9/2) = 1.80 mol L^−1 s^−1
Therefore, the rate at which O2 is reacting is 1.80 mol L^−1 s^−1.
2. The rate at which CO2 is being formed is also directly proportional to the rate at which C3H6 is reacting. Therefore, the rate at which CO2 is being formed is 0.40 mol L^−1 s^−1.
3. The rate at which H2O is being formed is half the rate at which C3H6 is reacting. Therefore, the rate at which H2O is being formed is:
(0.40 mol L^−1 s^−1) / 2 = 0.20 mol L^−1 s^−1
4. The rate at which CO2 is being formed cannot be directly determined from the given information. We can only say that it is proportional to the rate of C3H6.
5. The rate at which H2O is being formed cannot be directly determined from the given information. We can only say that it is half the rate of C3H6.
6. The rate values found in options 1, 2, and 3 do not match the calculations and are therefore incorrect. However, option 4 is also incorrect since the rate of CO2 cannot be determined with the given information.
So, the correct answer is 6. none of the previous answers is correct.
To find the rates of the other species involved in the reaction, we can use the stoichiometry of the reaction. The stoichiometric coefficients in the balanced equation tell us the ratio in which the reactants and products are consumed and produced.
Given that the rate of C3H6 is 0.40 mol L^(-1)s^(-1), we can determine the rates of the other species by looking at the stoichiometric coefficients.
1. The stoichiometric coefficient of O2 in the balanced equation is 9, which means that for every 2 moles of C3H6 reacting, 9 moles of O2 are also reacting. Therefore, the rate at which O2 is reacting is (9/2) * (0.40 mol L^(-1)s^(-1)) = 1.8 mol L^(-1)s^(-1).
2. The stoichiometric coefficient of CO2 in the balanced equation is 6, which means that for every 2 moles of C3H6 reacting, 6 moles of CO2 are being formed. Therefore, the rate at which CO2 is being formed is (6/2) * (0.40 mol L^(-1)s^(-1)) = 1.2 mol L^(-1)s^(-1).
3. The stoichiometric coefficient of H2O in the balanced equation is 6, which means that for every 2 moles of C3H6 reacting, 6 moles of H2O are being formed. Therefore, the rate at which H2O is being formed is (6/2) * (0.40 mol L^(-1)s^(-1)) = 1.2 mol L^(-1)s^(-1).
From the calculations, we can see that none of the given options match the rates of formation or consumption for CO2 and H2O. Therefore, the correct answer is option 6: none of the previous answers is correct.