Question

A sample of glucose, C6H12O6, contains 1.270×10²¹ carbon atoms.
1.How many atoms of hydrogen does it contain?

2.How many molecules of glucose does it contain?

3.How many moles of glucose does it contain?

4.What is the mass of this sample in grams?

Answer 1

Mole of Carbon (C) = Atoms of C / Avogadro number = 1.270*10^21 / 6.023*10^23 = 0.0021086 moles

C6H12O6

From formula;

3) 6 moles of C are contained in 1 mole of Glucose

So, 0.0021086 moles of C will be contained in = 0.0021086/6 = 0.000351433 moles of Glucose.

Moles of Glucose = 0.000351433 moles

2) Molecules of Glucose = 0.000351433 * 6.023 * 10^21 = 2.17*10^20 molecules .....Answer

4) Mass of glucose = moles * molar mass = 0.0003514333*180.156 = 0.0633 grams ....Answer

1)

Moles of H = 12 * moles of Glucose = 12 * 0.000351433 = 0.0042172 moles

Atoms of H = 0.0042172 * 6.023 * 10^23 = 2.54*10^21 atoms of H .....Answer

Let me know if any doubts/answer is not matching.