Answer:
56 g. Option 3.
Explanation:
The reaction is: CaCN₂ + 3H₂O → CaCO₃ + 2 NH₃
1 mol of calcium cianide reacts with 3 moles of water in order to produce 1 mol of calcium carbonate and 2 moles of ammonia
We have the mass of each reactant, so let's convert the mass to moles:
45 g. 1mol / 80.08 g = 0.562 moles of cianide
45 g. 1mol / 18 g = 2.5 moles of water
The cianide is the limiting reactant:
3 moles of water need 1 mol of cianide to react
Then, 2.5 moles of water will need (2.5 . 1)/ 3 = 0.833 moles
As we have 0.562 moles of CN⁻ we don't have enough
We can work now, on the reaction:
Ratio is 1:1. Therefore 0.562 moles of cianide will produce 0.562 moles of carbonate
Let's convert the mass to moles to find the answer:
0.562 mol . 100.08 g / 1 mol = 56.2 g
