A 10.17-g sample of solid sodium bicarbonate (the active ingredient in baking soda) completely decomposes into solid sodium hydroxide and carbon dioxide gas when heated. After the sodium hydroxide cools, it has a mass of 4.84 g. According to the law of conservation of mass, what mass of carbon dioxide must have been formed?

5.33 g

Explanation:

Let's consider the balanced reaction for the complete decomposition of solid sodium bicarbonate to form solid sodium hydroxide and carbon dioxide gas when heated.

NaHCO₃(s) → NaOH(s) + CO₂(g)

According to Lavoisier's law of conservation of mass, the sum of the masses of the reactants is equal to the sum of the masses of the products. Then,

m(NaHCO₃) = m(NaOH) + m(CO₂)

m(CO₂) = m(NaHCO₃) - m(NaOH)

m(CO₂) = 10.17 g - 4.84 g

m(CO₂) = 5.33 g

the answer is option a.