The question requires us to calculate the amount of ammonia (NH3) formed when 130 g of Ca(OH)2 react with NH4Cl.
The balanced chemical equation provided by the question shows us that the stoichiometric relation between Ca(OH)2 and NH3 is as it follows:
1 mol Ca(OH)2 ------------------- 2 mol NH3
Since the amount of NH4Cl that is involved in the reaction is not informed, we'll assume that Ca(OH)2 acts as the limiting reactant and we'll use the amount of Ca(OH)2 provided to calculate the amount of NH3 produced. To do that, we'll need to convert the mass given (130g) in number of moles, calculate the amount of NH3 produced, in moles, and convert this value to grams using the molar mass of NH3.
- number of moles of Ca(OH)2
We'll use the molar mass of Ca(OH)2 to calculate how many moles are there in 130g of this compound (atomic mass of Ca = 40.08u, atomic mass of O = 15.99u and atomic mass of H = 1.007u):
molar mass of Ca(OH)2 = (1 * 40.08) + (2 * 15.99) + (2 * 1.007) = 74.07 g/mol
As the molar mass of Ca(OH)2 is 74.07 g/mol, we can write:
74.07g Ca(OH)2 ------------------- 1 mol
130g Ca(OH)2 ---------------------- x
Solving for x, we'll have that 130g of Ca(OH)2 corresponds to 1.755 moles of this compound.
- amount of NH3 produced, in moles:
Now, using the amount of Ca(OH)2 in mol (1.755 moles) and the stoichiometric relation from the chemical equation, we can write:
1 mol Ca(OH)2 ------------------- 2 mol NH3
1.755 mol Ca(OH)2 ------------- y
Solving for y, we'll have that 3.510 moles of NH3 will be produced.
- amount of NH3, in grams
Next, we can use the molar mass of NH3 to convert the number of moles obtained (3.510 moles) to mass of NH3. The atomic mass of N is 14.01u and the atomic mass of H is 1.007u:
molar mass of NH3 = (1 * 14.01) + (3 * 1.007) = 17.03 g/mol
As the molar mass of NH3 is 17.03 g/mol, we can write:
1 mol NH3 ---------------- 17.03 g NH3
3.510 mol NH3 --------- z
Solving for z, we'll have that 3.510 moles of NH3 corresponds to 59.78 g of NH3.
Therefore, 3.510 mol or 59.78g of NH3 would be produced from 130g of Ca(OH)2.