What mass of water is needed to dissolve 292.5 g of NaCl to produce a .25 m aqueous solution?

Answer 1

NaCl is a salt, so it will dissociate completely in water. In order to find the volume of H2O needed to make a solution concentration of 0.25M with 282.5g of NaCl, you just need to do some conversions. To get the volume of water needed:

292.5g NaCl x (1mol NaCL/58.5g NaCl) x (1L H2O/0.25mol NaCl) = 20L H2O

What I did here was take the mass of the NaCl that you have and changed it to moles of NaCl (in one mole of NaCl there are 58.5g). Next I divided by the solution concentration that you wanted (0.25M is equal to 0.25mol of NaCl per liter of H2O). The answer is 20.L of H20.

Since you want the mass of water you need to multiply volume of water you have by the density:

20L x (1kg H2O/ 1L H20) = 20kg of H2O.

Hope this helps!

Answer 2

I beleive 20 liters of water will produce that. 14.6 g of NaCl per 1 liter of water is a .25 M solution....when you divide 292.5 g by 14.6 g you get 20.

Answer 3

0.25 m means 0.25 mol NaCl in 1 kg of water.

First, convert the mass of NaCl into moles by dividing by the molar mass of NaCl. Then, if you divide that number of moles by 0.25 mol/kg, your answer will be the mass of water (in kg) that you need to produce the 0.25 m solution.

Answer 4

since M=n"no of moles"/v"volume in littre"-------(1)
n=wt/M.wt
n=292.5/(22.99+35.45)=5

from the low no 1

v=n/M
so
v=5/.25=20 littre

since the d"density"=m"mass"/v"volume
and since the denistry of water = 1
so
1=m/20
so mass of water = 20 gm