Answer:
(a) oxygen
(b) 154g (to 3sf)
(c) 79.9% (to 3sf)
Explanation:
mass (g) = moles × Mr/Ar
note: eqn means chemical equation
(a)
moles of P = 84.1 ÷ 30.973 = 2.7152 moles
moles of O2 = 85÷2(16) = 2.65625 moles
Assuming all the moles of P is used up,
moles of O2 / moles of phosphorus = 5/4 (according to balanced chemical eqn)
moles of O2 required = 5/4 × 2.7152moles = 3.394 moles (more than supplied which is 2.65625moles)
therefore there is insufficient moles of O2 and the limiting reactant is oxygen.
(b)
moles of P2O5 produced
= 2/5 (according to eqn) × 2.7152
= 1.08608moles
mass of P2O5 produced
= 1.08608 × [ 2(30.973) + 5(16) ]
= 154.164g
= approx. 154g to 3 sig. fig.
(c)
% yield = actual/theoretical yield × 100%
= 123/154 × 100%
= 79.870%
= approx. 79.9% (to 3sf)
Answer:
B. Salt, NaCl, is produced by the process of evaporation of seawater or brine. If the surface area of the water is increased, the same volume of water evaporates faster.
C. The Haber process combines hydrogen and nitrogen to make ammonia. The two gases are passed through a reactor under pressure and at high temperatures. If iron is added to the reactor, the yield of ammonia increases.
Explanation:
Evaporation of water is responsible for the production of sodium chloride also known as table salt. Sodium and chlorine are present in water. When more evaporation of water occurs, sodium and chlorine come close together forming sodium chloride. Haber process is responsible for the production of ammonia which is used as fertilizer. For speed up the process, catalyst is used such as iron in order to complete the reaction in less time. Iron binds hydrogen and nitrogen with each other.
