Respuesta :
Formula to find the percent composition of an element in a compound is [tex]\frac {MolarMassOfElement}{MolarMassOfCompound}*100[/tex].
Now enter the variables into the formula.
[tex]\frac {12.4}{78.0}*100 = 15.897[/tex]%
Round to 3 significant figures. 15.897% = 15.9%
The answer is 15.9% H
Now enter the variables into the formula.
[tex]\frac {12.4}{78.0}*100 = 15.897[/tex]%
Round to 3 significant figures. 15.897% = 15.9%
The answer is 15.9% H
Answer:
The percentage by mass of hydrogen in the unknown compound is 15.9 %
Explanation:
The formula to be used here is
% by mass of an element in a compound =
(molar mass of the element ÷ molar mass of the compound) × 100
From the question, the mass of the element (Hydrogen) is 12.4 g
The mass of the compound (unknown) is 78.0 g
Hence,
% by mass of hydrogen in the unknown compound = (12.4 ÷ 78) × 100
= 15.9 %