# Quiz | Chemical Calculations for Solutions

1

Which of the following factors affects the solubility of a particular substance?

Solubility is the maximum quantity of solute dissolvable in a solvent at a particular temperature. A solid is more soluble at higher temperatures and in a solvent with similar types of intermolecular forces

2

What is the molarity of a solution that contains 8 moles of solute in 2 liters of solution?

Molarity M  =  $\frac{{\mathrm{n}}_{\mathrm{solute}}}{{\mathrm{V}}_{\mathrm{solution}}}$  =  $\frac{8}{2}$ =  4M

3

What is the mass of NaCl in 250 mL of a 0.4 M solution?

number of moles nNaCl  =  M x Vsolution  =  $\frac{{\mathrm{m}}_{\mathrm{NaCl}}}{{\mathrm{M}}_{\mathrm{NaCl}}}$

⇒ mNaCl  = M x Vsolution x MNaCl   with MNaCl = molar mass of NaCl = MNa + MCl = 23.0 + 35.4 = 58.4 g.mol-1

⇒ mNaCl  = 0.4 x 0.250 x 58.4 = 5.84 g

4

What does not change when a solution is diluted by the addition of solvent?

In dilution, the amount of solute does not change: the number of moles are the same before and after dilution

5

How many mL of a 2.0 M NaBr solution are needed to make 300.0 mL of 0.5 M NaBr?

In dilution, the amount of solute does not change: n1 = n2 ⇒ M1 x V1 = M2 x V2
2.0 x V1 = 0.5 x 0.300 ⇒ V1 = 0.075 L = 75 mL

6

What is the endpoint of a titration?