Chemistry help..solubility?

Question

I'm working on my summer assignment..and have about ten questions that look like this, and I dont know how to do any of them, any guidance would be appreciated greatly.

The solubility of ammonium bromide in water at 20 degrees C is 75.5g/100g water. Its solubility at 50 degrees C is 99.2g/100g water. Calculate:

the mass of ammonium bromide that dissolves in 62g of water at 20 degrees C

this is confusing the heck out of me..please help!

Answer 1

you know that 75.5g NH4Br dissolves in 100g of water so you can work out that 0.755g would dissolve in 1g water (75.5/100)

you have 62g water so you could dissolve (0.755 * 62) g NH4Br in 62g

answer 46.8g ammonium bromide

Answer 2

At 20°, 75.5 g/100 g H2O

So, per 62 g H2O, you will be able to dissolve (75.5×62)/100 = 46.81 g ammonium bromide.

Answer 3

it is 46.8g of ammonium bromide.. the solubility at 50dg may be just given to create a little confusion