Question

Calculate the number of moles of NaHCO₃ (sodium bicarbonate, or baking soda) in a 5.0 g sample of this substance.

Group of answer choices
A. 2.8 × 10²³ mole
B. 0.060 mole
C. 420 moles
D. 3.6 × 10²² moles
E. 0.096 mole

Answer 1

To calculate the number of moles of NaHCO₃ in the sample, we need to first determine its molar mass. Next, we can calculate the molar mass of NaHCO₃ by adding up the molar masses of each element. Finally, to calculate the number of moles, we use the formula: moles = mass / molar mass. Option B is correct.

Step-by-step explanation:

To calculate the number of moles of NaHCO₃ in the sample, we need to first determine its molar mass. NaHCO₃ consists of sodium (Na), hydrogen (H), carbon (C), and oxygen (O). The molar masses of these elements are: Na = 22.99 g/mol, H = 1.01 g/mol, C = 12.01 g/mol, and O = 16.00 g/mol.

Next, we can calculate the molar mass of NaHCO₃ by adding up the molar masses of each element: molar mass NaHCO₃ = (1 × Na) + (1 × H) + (1 × C) + (3 × O) = (1 × 22.99) + (1 × 1.01) + (1 × 12.01) + (3 × 16.00) = 84.01 g/mol.

Finally, to calculate the number of moles, we use the formula:

moles = mass / molar mass.

Substituting the given mass (5.0 g) and the calculated molar mass (84.01 g/mol) into the formula, we get:

moles = 5.0 g / 84.01 g/mol = 0.0595 mol (rounded to 0.060 mol).