Question

If sea water has a density of 1.025 kg/L and 3.5% of the mass in sea water is salt, determine the mass of salt dissolved in 500 gallons of sea water

Answer 1

68 kg. There are 58 kg salt in 500 gal seawater.

Step 1. Convert gallons to litres

1 US gal = 3.79 L (1 Imp gal = 4.55 L)

Step 2. Find the volume of the seawater

Volume = 500 gal × (3.79 L/1 gal) = 1895 L

Step 3. Find the mass of the seawater

Mass = 1895 L × (1.025 kg/1 L) = 1942 kg

Step 4. Find the mass of the salt

Mass of salt = 1942 kg seawater × (3.5 kg salt/100 kg seawater) = 68 kg salt