ANSWER: 39.7%
Explanation:
1. Determine your chain's density first.
Mass / volume equals density.
volume equals water displaced ml = 20 ml
- 15 ml = 5 ml where volume = Volume of Final Level of Water - Initial Level of Water
Mass = 66.7 g
Density is equal to 66.7g/5 ml, or 13.34 g/ml.
2. Next, calculate the chain's density as the weighted average of its component densities.
Divided by the mass of the chain, the formula is: mass of gold, density of gold, mass of other metals, density of other metals.
If x is the weight of gold, then 66.7 - x is the weight of the other metals:
19.3 - 2 + 9.7 . (66.7
66.7
= 13.34
19.32 + 635.66 - 9.72
= 889.778
9.62
254.118
2 = 26.47
Then, there are 26.47 grams of gold in 66.7
grams of chain, which yields a percentage of:
(26.47 / 66.7) × 100 = 39.7%