The equation is:
CuSO4(s) + Zn(s) -> Cu(s) + ZnSO4(aq)
3.22 g of powdered zinc is added to 200ml of 0.5M copper sulfate solution.
What mass of copper is deposited?
Hi guys. I am confused about the stoichmetry question.
Q: The equation is:
CuSO4(s) + Zn(s) -> Cu(s) + ZnSO4(aq)
3.22 g of powdered zinc is added to 200ml of 0.5M copper sulfate solution.
What mass of copper is deposited?
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I found the mol of CuSO4 to be 0.1 and mol of Zn to be 0.049 mol.
To figure out the mass of Cu, why can't I use either of those moles(because the coefficient are the same!)? I looked in the answer and I had to use 0.049(Zn's mol) why not CuSO4's mol as the answer is 3.15g Please let me know. Thanks so much!
You need to understand that this is a limiting reagent problem. The reason you can't use EITHER Zn or CuSO4 is because one of them will be used up before the other is; i.e., one reagent will be used and the other one will be in excess.
mols CuSO4 = 0.1
mols Zn = 3.22/65.4 = 0.049
Now use the coefficients to convert mols each to mols Cu.
For CuSO4 that is 0.1 x (1 mol Cu/1 mol CuCO4) = 0.1 mol Cu produced.
For Zn that is 0.049 x (1 mol Cu/1 mol Zn) = 0.049
You can see the mols Cu produced is NOT the same which means 0.049 mols Cu will be produced (you can't get 0.1 because there isn't enough Zn present). So Zn is the limiting reagent, all of it will be used, there will be Cu left unreacted.
So 0.049 mol Cu will be produced and that is 0.049 x 63.55 = 3.22. I don't know what numbers your answer book used to get 3.15 but my periodic table numbers give 3.22. Technically you aren't allowed but one significant figure either so the answer should be rounded to 3.
Ah, the world of stoichiometry, where atoms and equations dance together! Let's unravel this chemical tango, shall we?
In the given equation, we see that zinc (Zn) reacts with copper sulfate (CuSO4) to produce copper (Cu) and zinc sulfate (ZnSO4). The equation is balanced as follows:
CuSO4(s) + Zn(s) -> Cu(s) + ZnSO4(aq)
Now, you're on the right track with finding the moles of CuSO4 and Zn. A mole of a substance is a unit that represents 6.022 x 10^23 particles, so it helps us compare different substances in a reaction.
Since you've found that the moles of Zn is 0.049 mol, that means 0.049 mol of Zn reacted with the given amount of CuSO4.
Now, let's take a closer look at the stoichiometry of the reaction. From the balanced equation, we can see that the coefficient of Zn is 1, while the coefficient of CuSO4 is also 1. This means that 1 mole of Zn reacts with 1 mole of CuSO4.
So, when we know that 0.049 mol of Zn reacted, we can say that an equal number of moles of Cu are being produced. Therefore, the number of moles of Cu deposited is also 0.049 mol.
To find the mass of Cu, we need to multiply the number of moles by the molar mass of Cu, which is 63.55 g/mol. So, mass = moles * molar mass.
Mass of Cu = 0.049 mol * 63.55 g/mol = 3.11 g
Ah, there you have it! The mass of copper deposited is approximately 3.11 grams.
Remember, stoichiometry can be a merry dance, and it helps us determine the relationships between substances in a chemical reaction. Keep practicing, and you'll master it in no time!
To find the mass of copper deposited, you need to use the stoichiometric ratio between zinc and copper in the balanced chemical equation.
The balanced equation is: CuSO4(s) + Zn(s) -> Cu(s) + ZnSO4(aq)
From the given information, you have determined that the moles of Zn is 0.049 mol.
The stoichiometric ratio between Zn and Cu in the balanced equation is 1:1. This means that for every 1 mol of Zn, 1 mol of Cu is produced.
Therefore, since you have 0.049 mol of Zn, you can conclude that 0.049 mol of Cu is also produced.
To find the mass of Cu, you need to use the molar mass of Cu, which is 63.55 g/mol.
Mass of Cu = moles of Cu × molar mass of Cu
= 0.049 mol × 63.55 g/mol
≈ 3.15 g
So the mass of copper deposited is approximately 3.15 g.
To determine the mass of copper deposited, you need to use the stoichiometric ratio between zinc and copper in the balanced equation.
From the equation: CuSO4(s) + Zn(s) -> Cu(s) + ZnSO4(aq), you can see that the coefficient in front of Cu(s) is 1, which means for every 1 mole of zinc (Zn) reacted, 1 mole of copper (Cu) is deposited.
You correctly found the number of moles of zinc to be 0.049 mol. This tells us that 0.049 moles of zinc will react to form 0.049 moles of copper.
To find the mass of copper deposited, you can use the molar mass of copper (63.55 g/mol). Multiply the number of moles of copper by the molar mass:
0.049 mol x (63.55 g/mol) = 3.10 g
So the mass of copper deposited is 3.10 g.
To clarify why you can't use the moles of CuSO4 to find the mass of copper deposited, it is because CuSO4 is the reactant and not the product that we are interested in. The balanced equation tells us the stoichiometric ratio between zinc and copper, so we need to use the moles of zinc to calculate the mass of copper.