As per the gold standard, the purest form of gold will have 24 karats.
The given chain has 14 karat gold.
Therefore, the percentage of pure gold = 14/24 = 0.5833 or 58.33%
If the total chain weighs 2.8 ounces, then the total weight if gold in the chain = 0.5833*2.8 ounces (since the % of pure gold is only 58.33%)
The total weight if gold in the chain = 0.5833*2.8 = 1.633... = 1.63 ounces (Rounded to two decimal places)