Answer:
7.5 % of Ag
Explanation:
Total mass of sterling silver chain is:
Mass of silver + Mass of copper
33.3 g Ag + 2.70g of Cu = 36 g
% of Silver is (mass of silver / total mass) . 100 →
(2.70 g / 36 g) . 100 → 7.5%
The believe the answer is A
Answer:
Percent yield = 65.2 %
Explanation:
The reaction determines this:
2 moles of Al react to 3 moles of chlorine gas in order to produce 2 mol of aluminum chloride.
We determine the moles of chlorine:
52 g . 1mol /70.9g = 0.733 moles of Cl₂
3 moles of gas can produce 2 moles of salt
Then, our 0.733 moles may produce (0.733 . 2) / 3 = 0.489 moles of AlCl₃
We convert moles to mass to predict the 100 % yield
0.489 mol . 133.3 g /mol = 65.19 g
Percent yield = (Yield produced / 100 % yield) . 100
Percent yield = (42.5 g / 65.19g) . 100 = 65.2 %
