Question

Determine the number of atoms of C in 15.0 grams of C₆H₁₂O₆.

Answer 1

Glucose is an organic molecule or particularly a reducing hexaaldose whose molecular formula is C6H12O6. Hence, from molecular formula itself we can calculate that it's molar mass is 180 g/mole.

So turning back to the question.

180 g of glucose = 1 mole of glucose

Hence, 18 g of glucose =  (  1/180)∗18  moles =0.1 moles

Now 1 mole of glucose contains  6.022∗1023  molecules of glucose. (Avogadro′sNumber)  

This implies that 0.1 Moles of glucose should contain

= 0.1∗(6.022∗1023)=6.022∗1022  molecule of glucose

Now for 1 molecule of glucose,there are 6 atoms of Carbon (as from the molecular formula of glucose) present in it.

Thus number of molecules of carbon in  6.022∗1022  molecules of glucose must be =  6∗(6.022∗1022)=36.132∗1022  atoms of carbon.

Hope I am able to clear the answer.