How do you make a 10 percent salt solution using a gallon container this is urgent?

Answer 1

You will need additional equipment if you start from solid salt and need exactly 10% solution.

But if this is not a serious exact 10%, say 10 - 12 %, then this is another matter.

First, soak the salt in the water overnight, you will need to add around 1/2 salt into the gallon and fill the rest with water. The saturate salt solution is about 38% volume and density around 1.2 kg/L.

Scoop out all the excess salt from gallon, pour out water until you got half the salt solution in it. Fill the water to bring the level to full gallon, stir or shake well. At this stage, you will get about 20% salt solution. (Actually about 20.7% concentration and the density is around 1.15 kg/L)

Pour out half the water and fill in with fresh water again, now, you got your 10% salt solution. (Actually about 11% concentration)

This should be close enough.