# What is the mass of sulfate of ammonia that can be obtained from 1.00 tonne of sulfuric acid and 0.500 tonne of ammonia?

Apr 22, 2017

Well, we need (i) a stoichiometric equation..............and get $B$.

#### Explanation:

$2 N {H}_{3} + {H}_{2} S {O}_{4} \rightarrow {\left(N {H}_{4}\right)}_{2} S {O}_{4}$.

Two equiv of ammonia react with one equiv sulfuric acid to give one equiv of the salt, $\text{ammonium sulfate}$. This is an acid-base reaction.........

And so we calculate the molar equivalence of each of the given reagents.......(ii)

$\text{Moles of sulfuric acid} = \frac{1000 \times {10}^{3} \cdot g}{98.08 \cdot g \cdot m o {l}^{-} 1} = 10.2 \times {10}^{3} \cdot m o l .$

$\text{Moles of ammonia} = \frac{500 \times {10}^{3} \cdot g}{17.03 \cdot g \cdot m o {l}^{-} 1} = 29.4 \times {10}^{3} \cdot m o l .$

Now clearly, there is a STOICHIOMETRIC excess of ammonia. Agreed? And the limiting reagent is sulfuric acid. At equivalence, there are $10.2 \times {10}^{3} \cdot m o l$ of ammonium sulfate.........

This represents a mass of $10.2 \times {10}^{3} \cdot m o l \times 132.14 \cdot g \cdot m o {l}^{-} 1$

$= 1348 \cdot k g$, i.e. $1.35 \cdot \text{tonne}$, and so you know which option.......

Now this is a hard question for an A-level student, or even a 1st year chem student. But all I have done is to (i) write the stoichiometric equation, and (ii) calculated the molar equivalence; and this is made difficult here because they quote mass in $\text{TONNES}$ rather than the more familiar $\text{grams}$ (and this is why I converted the mass to grams initially - chemists typically work in gram quantities). I agree that this is a lot of work for a multiple choice question.

As to the second part of your question, ammonia, is a BASIC species. It undergoes an acid base reaction in water according to the following reaction.........

$N {H}_{3} + {H}_{2} O r i g h t \le f t h a r p \infty n s N {H}_{4}^{+} + H {O}^{-}$;

were I do to this with hydrochloric acid, I would get:

$N {H}_{3} \left(a q\right) + H C l \left(a q\right) \rightarrow N {H}_{4} C l \left(a q\right)$

SOME POINTS TO CONSIDER............

$\text{Ammonium chloride}$ or $\text{ammonium sulfate}$ ARE SALTS............

$\text{Ammonia}$ is a colourless gas, $N {H}_{3} \left(g\right)$, with a foul, penetrating odour. We can make aqueous solution of ammonia (ammonia gas has substantial water solubility), but the dominant species in solution is the free-base, $N {H}_{3}$, and there only small equilibrium quantities of ammonium ion. This is knowledge that I would expect of a 1st year university student, or of a good A level student.