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.

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

 

1.9 grams

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na