Question

(i) Calculate the no. of molecules in 56 g of CH4 (Methane)
(ii) Calculate the numbers of atoms in 1 g. of Magnesium.​

Answer 1

Answer:

(1) number of molecule = (given mass /molar mass) avagadro number

$\frac{56}{16} \times 6.022 \times 10 {}^{23} \\ 21.077 \times 10 {}^{23} \\ 2.1077 \times 10 {}^{24} molecules \\ (2) \: number \: of \: atoms = \frac{given \: mass}{molar \: mass } \times 6.022 \times 10 {}^{23} \\ = \frac{1}{24} \times 6.022 \times 10 {}^{23 } \\ \frac{3011}{12 \times 1000} \times 10 {}^{23} \\ \frac{250.9}{1000} \times 6.022 \times 10 {}^{23} \\ 2.509 \times 10 {}^{22} atoms$