Question

How many moles of sucrose, C₁₂H₂₂O₁₁, are in a 25-g sample of sucrose?

Short answer

No. of moles of sucrose is equal to $0.073\mathrm{m}\mathrm{o}\mathrm{l}$

Step-by-step solution

Determine molecular mass 

To calculate no of moles of sucrose, we have to evaluate the molar mass of sucrose first.

Element	Quantity		Molar mass (g/mol element)		Subtotal (g/mol compound)
C	12	×	12.01	=	144.12
H	22	×	1.008	=	22.176
O	11	×	16.00	=	176.00
			Molecular mass(g/mol)	=	342.296

Determine no of moles

No of moles = $25\mathrm{g}\mathrm{s}\mathrm{u}\mathrm{c}\mathrm{r}\mathrm{o}\mathrm{s}\mathrm{e}\times \frac{\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{o}\mathrm{f}\mathrm{s}\mathrm{u}\mathrm{c}\mathrm{r}\mathrm{o}\mathrm{s}\mathrm{e}}{342.296\mathrm{g}\mathrm{s}\mathrm{u}\mathrm{c}\mathrm{r}\mathrm{o}\mathrm{s}\mathrm{e}}=0.073\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{o}\mathrm{f}\mathrm{s}\mathrm{u}\mathrm{c}\mathrm{r}\mathrm{o}\mathrm{s}\mathrm{e}$

Hence, no of moles of sucrose is equal to$0.073\mathrm{m}\mathrm{o}\mathrm{l}$