Calculate the mass of carbon dioxide in which there are so many molecules in 4.5 g of water?

Given:
m (H2O) = 4.5 g
N (CO2) = N (H2O)

To find:
m (CO2) -?

1) M (H2O) = Mr (H2O) = Ar (H) * N (H) + Ar (O) * N (O) = 1 * 2 + 16 * 1 = 18 g / mol;
2) n (H2O) = m (H2O) / M (H2O) = 4.5 / 18 = 0.25 mol;
3) N (H2O) = n (H2O) * NA = 0.25 * 6.02 * 10 ^ 23 = 1.505 * 10 ^ 23;
4) n (CO2) = N (CO2) / NA = 1.505 * 10 ^ 23 / 6.02 * 10 ^ 23 = 0.25 mol;
5) M (CO2) = Mr (CO2) = Ar (C) * N (C) + Ar (O) * N (O) = 12 * 1 + 16 * 2 = 44 g / mol;
6) m (CO2) = n (CO2) * M (CO2) = 0.25 * 44 = 11 g.

Answer: The mass of CO2 is 11 g.