Answer: The percentages of carbon and hydrogen numerically to four significant figures is [tex]83.33\%[/tex] and [tex]16.67\%[/tex] respectively.
Explanation:
Molar mass of the compound is the mass of 1 mole of compound which is the sum of masses of each element.
Mass of 1 mole of compound= mass of carbon + mass of hydrogen+ = 5(12) + 12(1)= 72 g.
a) Percentage by mass of carbon =[tex]\frac{\text {mass of carbon}}{\text {Total mass}}\times 100\ %[/tex]
Percentage by mass of carbon =[tex]\frac{60}{72}\times 100\%=83.33\%[/tex]
b) Percentage by mass of hydrogen =[tex]\frac{\text {mass of hydrogen}}{\text {Total mass}}\times 100\ %[/tex]
Percentage by mass of hydrogen =[tex]\frac{12}{72}\times 100\%=16.67\%[/tex]
