Question

If a 1.85 g mass of zinc produces 475 mL of gas and your balloon weighs 0.587 g and the room temperature is 19.0°C. Calculate the amount of zinc needed to produce enough gas to get your balloon airborne by adding 1 mL to the required balloon volume so that its density is less than that of the surrounding air.

Answer 1

Density of air at 19degC = 0.001204 g/mL

assuming that density of zinc = density of air:

volume zinc = 0.587 g / (0.001204 g/mL) = 487.54 mL

then the mass zinc required is:

mass zinc = 487.54 mL * (1.85 g / 475 mL) = 1.9g

Answer:

1.9 grams