Q.1 Calculate the number of atoms of carbon present in 25 g of CaCO3.
Answer :
Given,
Wt. of CaCO3 = 25 g
No . of moles of CaCO3 = Wt. given / mol. weight = 25/ 100 = 0.25 mole
(Wt of CaCO3 = 40 + 12 + 48 = 100 )
Again, 1 mole of CaCO3 contains 1 mol of C
0.25 mol of CaCO3 contains 0.25 mol of C
We Know that,
1 mole of C contains 6.022 * 10 23 atoms of C
0.25 mole of C contains 0.25 * 6.022 * 10 23 atoms of C
= 1.5055 * 10 23 atoms of C.