Nh3+Cuo=N2+Cu+H2O, 18.1g of nh3 and 90.4g of CuO made to react. (a). Determine the limiting reagent. (b). Which reactant is in excess? (c). Calculate the mass of Cu that forms. (d). Calculate the volume in liter of n2 that form at STP.
Aque
To determine the limiting reagent, we need to compare the amounts of reactants used with the stoichiometric ratio in the balanced equation. The balanced equation is:
2 NH3 + 3 CuO → N2 + 3 Cu + 3 H2O
(a) First, we need to calculate the number of moles for each reactant:
Molar mass of NH3 (ammonia) = 14.01 + 1.01 × 3 = 17.04 g/mol
Number of moles of NH3 = 18.1 g / 17.04 g/mol = 1.06 mol
Molar mass of CuO (copper(II) oxide) = 63.55 + 16.00 = 79.55 g/mol
Number of moles of CuO = 90.4 g / 79.55 g/mol = 1.14 mol
Next, let's compare the mole ratios of NH3 and CuO to the balanced equation:
For NH3: CuO : 2 : 3
For 1.06 mol of NH3, the stoichiometric ratio gives us: (1.06 mol NH3) x (3 mol CuO/2 mol NH3) = 1.59 mol CuO required.
Since we have 1.14 mol of CuO, which is less than the stoichiometric ratio calculated, CuO is the limiting reagent.
(b) The reactant in excess is NH3 since the stoichiometric ratio required only 1.59 mol CuO, but we have 1.06 mol of NH3.
(c) To calculate the mass of Cu formed, we need to use the stoichiometric ratio from the balanced equation:
From 3 mol Cu = 1 mol CuO, we have: (1.14 mol CuO) x (3 mol Cu/1 mol CuO) = 3.42 mol of Cu.
Molar mass of Cu = 63.55 g/mol
Mass of Cu formed = (3.42 mol Cu) x (63.55 g/mol) = 217.71 g of Cu.
So, the mass of Cu that forms is 217.71 g.
(d) To calculate the volume of N2 gas at STP, we need to use the ideal gas law (PV = nRT) and the molar volume of a gas at STP, which is 22.4 L/mol.
From the balanced equation, 2 mol NH3 produce 1 mol N2. Therefore, 1.06 mol NH3 will produce x mol N2:
(1.06 mol NH3) x (1 mol N2/2 mol NH3) = 0.53 mol N2.
Since 1 mol of any gas occupies 22.4 L at STP, the volume of N2 gas formed is:
Volume of N2 gas = (0.53 mol N2) x (22.4 L/mol) = 11.9 L at STP.
Therefore, the volume of N2 gas formed is 11.9 L at STP.
To determine the limiting reagent, you need to compare the number of moles of each reactant with their stoichiometric coefficient in the balanced chemical equation.
First, you want to convert the given masses of NH3 and CuO to moles using their molar masses:
Molar mass of NH3: 14.01 g/mol + 3(1.01 g/mol) = 17.04 g/mol
Molar mass of CuO: 63.55 g/mol + 16.00 g/mol = 79.55 g/mol
Number of moles of NH3 = 18.1 g / 17.04 g/mol = 1.0628 mol
Number of moles of CuO = 90.4 g / 79.55 g/mol = 1.1370 mol
Now, let's examine the balanced chemical equation:
NH3 + CuO → N2 + Cu + H2O
From the balanced equation, we see that the stoichiometric coefficient of NH3 is 1 and the stoichiometric coefficient of CuO is 1. Therefore, the molar ratio between NH3 and CuO is 1:1.
Since the number of moles of NH3 (1.0628 mol) and CuO (1.1370 mol) are roughly equal, neither reactant is present in excess. However, since we can't have a fractional number of moles, we can conclude that NH3 is the limiting reagent because there are slightly fewer moles of NH3 compared to CuO.
To calculate the mass of Cu that forms, we can use the stoichiometry of the balanced equation. The stoichiometric coefficient of Cu in the balanced equation is 1.
Mass of Cu = number of moles of CuO × molar mass of Cu
Mass of Cu = 1.1370 mol × 63.55 g/mol ≈ 72.29 g
Therefore, the mass of Cu that forms is approximately 72.29 g.
To calculate the volume of N2 at STP (Standard Temperature and Pressure), we can use the ideal gas law and the concept of molar volume.
1 mole of any ideal gas occupies 22.4 liters at STP.
From the balanced chemical equation, we see that the stoichiometric coefficient of N2 is also 1.
Number of moles of N2 = number of moles of Cu = 1.1370 mol
Therefore, the volume of N2 at STP is 1.1370 mol × 22.4 L/mol = 25.43 L.
Hence, the volume of N2 that forms at STP is approximately 25.43 liters.
First, balance the equation.
2NH3 + 3CuO = N2 + 3Cu + 3H2O
Now convert your grams to moles, and see which gets used up first.
For (d), recall that 1 mole of N2 occupies 22.4L of space.