If 13.2 kg of Al 2 O 3 ( s ) , 50.4 kg of NaOH ( l ) , and 50.4 kg of HF ( g ) react completely, how many kilograms of cryolite will be produced? mass of cryolite produced: kg Na 3 AlF 6

Answer : The mass of cryolite produced will be, 54.38 kg

Solution : Given,

Mass of = 13.2 kg  = 13200 g

Mass of = 50.4 kg  = 50400 g

Mass of = 50.4 kg  = 50400 g

Molar mass of = 101.9 g/mole

Molar mass of = 40 g/mole

Molar mass of = 20 g/mole

Molar mass of = 209.9 g/mole

First we have to calculate the moles of and .

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

From the balanced reaction we conclude that

The mole ratio of and is, 1 : 6 : 12

And, the ratio of given moles of and is, 129.54 : 1260 : 2520

From this we conclude that, is an excess reagent because the given moles are greater than the required moles and is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of

From the reaction, we conclude that

As, 1 mole of react to give 2 mole of

So, 129.54 moles of react to give moles of

Now we have to calculate the mass of

Thus, the mass of cryolite produced will be, 54.38 kg

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .