Concentration and Molarity

Water added to 50.0 mL of 5.00 mol/L HCl until the total volume is 250 mL. What is the molar concentration of HCl in the diluted solution?

• 1.00 mol/L

• 1.60 mol/L

• 2.10 mol/L

• 2.80 mol/L

What volume of water must be added to 25 mL of a 4.0 mol/L solution of potassium carbonate solution to dilute it to a concentration of 1.6 mol/L?

• 27.2 mL

• 29.4 mL

• 31.5 mL

• 38.0 mL

1.50 mL of a 0.0500 mol/L solution of calcium chloride (CaCl₂) was diluted with water to a volume of 10.0 L. What was the concentration of Cl^- ions in the diluted solution in ppm?

• 0.234 ppm

• 0.532 ppm

• 0.712 ppm

• 0.954 ppm

Concentrated sulfuric acid (H₂SO₄) is solid as an 18 mol/L solution. A company uses this concentrated solution to prepare 2.0 L bottles of 1.0 mol/L sulfuric acid. How many 2.0 L bottles can be prepared from each litre of concentrated solution?

• 7

• 8

• 9

• 10

What is the concentration of a standard solution of hydrated oxalic acid (H₂C₂O₄.2H₂O) prepared by dissolving 25.21 g of hydrated oxalic acid in 250.0 mL of deionised water?

• 0.1937 mol/L

• 0.2765 mol/L

• 0.3762 mol/L

• 0.7998 mol/L

Tags

NGSS.HS-PS1-7

What is the mass of Na₂CO₃ required to make a 500 mL standard solution of 0.400 mol/L Na₂CO₃?

• 21.2 g

• 23.4 g

• 25.8 g

• 27.3 g

Tags

NGSS.HS-PS1-7

What is the molar concentration of a saturated CuSO₄.5H₂O solution that contains 20 g of solute in 100 g of water at 20⁰C? (Assume that 1 g of water gives 1 mL of solution.)

• 0.52 mol/L

• 0.63 mol/L

• 0.80 mol/L

• 0.98 mol/L

A cleaning product distributor has a warehouse storing 180 containers of oven-cleaning solution. The volume of each container is 25.0 L and the concentration of sodium hydroxide (NaOH) in each is 1.65 mol/L. What is the total mass of NaOH in the container?

• 302 kg

• 256 kg

• 274 kg

• 297 kg

Tags

NGSS.HS-PS1-7

The HCl solution shown is a commercially available standard solution. The 2.50 L container has a concentration of 1.00 mol/L. What is the concentration of the solution in units of %(w/v)?

• 3.65%(w/v)

• 3.13%(w/v)

• 3.24%(w/v)

• 3.97%(w/v)

The saline solution shown is for eye drops and other medical purposes. The 15 mL dispenser contains 1.2 mg of sodium chloride (NaCl). Calculate the sodium chloride concentration in the eye drops in mg/L.

• 74 mg/L

• 80 mg/L

• 65 mg/L

• 87 mg/L