Question

What mass of silver nitrate must be dissolved in 200 g of water to prepare 20% solution

Answer 1

b

Explanation:

For starters, you know that a solution's molarity tells you the number of moles of solute present for every

1 L

of solution.

In your case, you have

molarity

=

0.100 mol

.

L

−

1

This means that for every

1 L

=

10

3

.

mL

your solution will contain

0.100 moles

of silver nitrate,

AgNO

3

. the solute.

Now, notice that your solution has a volume of

250 mL

=

10

3

.

mL

4

This means that in order to have a molarity of

0.100 mol L

−

1

, the solution must contain

0.100 moles AgNO

3

4

=

0.025 moles AgNO

3

Finally, to convert the number of moles to grams, use the molar mass of silver nitrate

0.025

moles AgNO

3

⋅

169.87 g

1

mole AgNO

3

=

4.2 g

−−−−

Answer 2

Answer: you can solve it using molarity or mass percent formula.