Percentage of gold in $14$ carat gold is (in $\%$)

$A$ hydrocarbon contains $85.7 \% C$. If $42 \, mg$ of the compound contains $3.01 \times 10^{20}$ molecules,the molecular formula of the compound will be

If $0.0833 \ mol$ of a carbohydrate contains $1 \ g$ of hydrogen and its empirical formula is $CH_2O$,determine its molecular formula.

Define Percentage Composition in a compound.

$0.5 \ g$ of hydrocarbon gave $0.9 \ g$ of water on combustion. The percentage of carbon in the hydrocarbon is:

An organic compound with a molecular weight of $60$ contains $C = 20\%$,$H = 6.67\%$,and $N = 46.67\%$,with the remainder being oxygen. Upon heating,the solid residue gives a violet color with alkaline copper sulfate solution. Identify the compound.