Question

How many C₄H₁₀ molecules are contained in 9.213 g of this compound? How many hydrogen atoms?

Short answer

No of molecules of C₄H₁₀ will be \(9.452 \times {10^{22}}\)

The no of atoms of hydrogen will be \(9.452 \times {10^{23}}\)

Step-by-step solution

Determine molecular mass

To calculate no of molecules in 9.213 g of that compound, we have to evaluate the molar mass of that compound.

Element	Quantity		Molar mass (g/mol element)		Subtotal (g/mol compound)
C	4	×	12.01	=	48.04
H	10	×	1.008	=	10.08
			Molecular mass(g/mol)	=	58.12

Determine number of C4H10 molecules 

No. of molecules of that compound in 9.213 g of that compound,

\(\begin{align}9.213{\rm{ g of }}{{\rm{C}}_{\rm{4}}}{{\rm{H}}_{10}} \times \frac{{{\rm{mol of }}{{\rm{C}}_{\rm{4}}}{{\rm{H}}_{10}}}}{{58.12{\rm{ g of }}{{\rm{C}}_{\rm{4}}}{{\rm{H}}_{10}}}} \times \frac{{6.022 \times {{10}^{23}}{\rm{ molecules of }}{{\rm{C}}_{\rm{4}}}{{\rm{H}}_{10}}}}{{{\rm{mol of }}{{\rm{C}}_{\rm{4}}}{{\rm{H}}_{10}}}}\\{\rm{ }} = 9.452 \times {10^{22}}{\rm{molecules of }}{{\rm{C}}_{\rm{4}}}{{\rm{H}}_{10}}\end{align}\)

Hence, no of molecules of C₄H₁₀ will be \(9.452 \times {10^{22}}\)

Determine number of hydrogen atom

No. of hydrogen atoms,

\(9.452 \times {10^{22}}{\rm{ molecules of }}{{\rm{C}}_4}{{\rm{H}}_{10}} \times \frac{{10{\rm{ H atoms}}}}{{1{\rm{ molecules of }}{{\rm{C}}_4}{{\rm{H}}_{10}}}} = 9.452 \times {10^{23}}{\rm{H atoms}}\)

Hence, the no of atoms of hydrogen will be \(9.452 \times {10^{23}}\)