Question

You use an analytical balance to measure the mass of a weigh boat and record a mass of 1.5624 g. You then add some NaHCO3 to the weigh boat and give the weigh boat to your lab partner to measure. Your lab partner mistakenly forgets to record all of the digits on the balance and records a mass of 1.92 g. What is the minimum number of grams of acetic acid that you would need to fully react with your NaHCO3

Answer 1

Answer:

0.2554g of acetic acid is the minimum mass you would need for a full reaction.

Explanation:

The minimum mass your partner could meadure is 1.9200 g. That means the mass of NaHCO₃ could be added is:

1.9200g - 1.5624g = 0.3576g of NaHCO₃ that reacts with acetic acid, (CH₃COOH), thus:

CH₃COOH + NaHCO₃ CH₃COO⁻Na⁺ + H₂O + CO₂

Moles in 0.3576g of NaHCO₃ (Molar mass: 84g/mol) are:

0.3576g of NaHCO₃ × (1mol / 84g) = 0.0042571 moles of NaHCO₃. As 1 mole of NaHCO₃ reacts with 1 mole of CH₃COOH: 0.0042571 moles of CH₃COOH

As molar mass of CH₃COOH is 60g/mol:

0.0042571 moles of CH₃COOH × (60g / 1mol) = 0.2554g of acetic acid is the minimum mass you would need for a full reaction.