Answer:
a) No molecules of hydrogen
b) four molecules of ammonia
c) four left molecules of nitrogen.
Explanation:
The balanced reaction between nitrogen and hydrogen molecules to give ammonia molecules is:

Thus one molecule of nitrogen will react with three molecules of hydrogen to give two molecules of ammonia.
We have six molecules of each nitrogen and hydrogen in the closed container and they undergo complete reaction it means the limiting reagent is hydrogen. For six molecules of nitrogen, eighteen molecules of hydrogen will be required.
So six molecules of hydrogen will react with two molecules of nitrogen to give four molecules of ammonia.
The product mixture will have
a) No molecules of hydrogen
b) four molecules of ammonia
c) four left molecules of nitrogen.
Answer is: 7,826 kg of cryolite.
Chemical reaction: Al₂O₃ + 6NaOH + 12HF → 2Na₃AlF₆ + 9H₂<span>O.
m(</span>Al₂O₃) = 12,1 kg = 12100 g.
n(Al₂O₃) = m(Al₂O₃) ÷ M(Al₂O₃).
n(Al₂O₃) = 12100 g ÷ 101,96 g/mol = 111,86 mol; limiting reactant.
m(NaOH) = 60,4 kg = 60400 g.
n(NaOH) = 60400 g ÷ 40 g/mol.
n(NaOH) = 1510 mol.
m(HF) = 60,4 kg = 60400 g.
n(HF) = 60400 g ÷ 20 g/mol = 3020 mol.
From chemical reaction: n(Al₂O₃) : n(Na₃AlF₆) = 6 : 2.
n(Na₃AlF₆) = 2 ·111,86 mol ÷ 6 = 37,28 mol.
m(Na₃AlF₆) = 37,28 mol · 209,94 g/mol.
m(Na₃AlF₆) = 7826,56 g = 7,826 kg.
Familiar substances that sublime readily include iodine , dry ice , menthol, and camphor. Sublimation is occasionally used in the laboratory as a method for purification of solids, for example, with caffeine.
It is B, because it is an eclipse.