Answer to Question #128150 in General Chemistry for Lawrence

Question

How many gramz and atoms of Oxygen are there in 15 grams of sodium bicarbonate(Molar mass of NaHCO3=84.01g/mol)

Answer 1

Proportion 1:

84.01 – 100 %

(16×3) – x %

x = 57.13 % - fraction of Oxygen in NaHCO₃

Proportion 2:

15 g – 100 %

y – 57.13 %

y = 8.57 g - mass of Oxygen in 15 g of NaHCO₃

A mole of oxygen atoms (with the formula O) contains 6.02×10²³ O atoms.

In this problem there are (8.57 / 16) = 0.535 moles of Oxygen atoms.

Total number of Oxygen atoms = 0.535×6.02×10²³ = 3.22×10²³ atoms.

Answer: 8.57 g and 3.22×10²³ atoms