What is the limiting reactant when 45.9g of CuO are exposed to 2.57 g of H2 according to the equation

CuO(s) + H2(g)−→Cu(s) + H2O(g) ?

1.CuO
2.Unable to determine.
3.H2
4.Neither is limiting.

From the ratio of molar masses according to the equation, find the required mass of H2 for 45.9 g of CuO.

If the required mass of H2 is greater than 2.57g, then the limiting reagent is H2. If the required mass of H2 is less than 2.56g, then the limiting reagent is CuO.

MM for CuO=79.545
MM for H2 =2.016
mass of H2 required for 45.9 g of CuO
= (2.016/79.545)*45.9
= 1.16 g

Draw conclusion regarding which compound is the limiting reagent.

Thanks friend!

You're welcome! :)

To determine the limiting reactant in a chemical reaction, you need to compare the amounts of each reactant based on their stoichiometric coefficients in the balanced equation.

In this case, the balanced equation is CuO(s) + H2(g) -> Cu(s) + H2O(g).

First, calculate the number of moles for each reactant:
Moles of CuO = mass of CuO / molar mass of CuO
Moles of CuO = 45.9 g / 79.55 g/mol (molar mass of CuO)

Next, calculate the number of moles for the H2 reactant:
Moles of H2 = mass of H2 / molar mass of H2
Moles of H2 = 2.57 g / 2.02 g/mol (molar mass of H2)

Now, compare the moles of each reactant to their stoichiometric coefficients in the balanced equation. The stoichiometric coefficients are the numbers in front of each reactant in the balanced equation.

From the balanced equation, you can see that the stoichiometric coefficient for CuO is 1, and the stoichiometric coefficient for H2 is also 1.

Therefore, the mole ratio between CuO and H2 is 1:1.

Now, compare the moles of CuO and H2:
If the moles of CuO are greater than the moles of H2, then CuO is in excess and H2 is the limiting reactant.
If the moles of H2 are greater than the moles of CuO, then H2 is in excess and CuO is the limiting reactant.

Calculate the moles for both reactants:
Moles of CuO = 45.9 g / 79.55 g/mol = 0.577 mol
Moles of H2 = 2.57 g / 2.02 g/mol = 1.27 mol

In this case, the moles of H2 (1.27 mol) are greater than the moles of CuO (0.577 mol). Therefore, CuO is the limiting reactant.

So, the correct answer is:
1. CuO.