Molarity Practice Problems

What is the molarity of a solution made by dissolving 5.00 moles of NaCl in 2.00 liters of solution?

Answer explanation

Molarity (M) is calculated as moles of solute divided by liters of solution. Here, M = 5.00 moles / 2.00 L = 2.50 M. Therefore, the molarity of the solution is 2.50 M.

You have 0.75 moles of HCl dissolved in 0.25 liters of solution. What is the molarity?

Answer explanation

To find molarity, use the formula M = moles/volume. Here, M = 0.75 moles / 0.25 L = 3 M. Thus, the molarity of the HCl solution is 3 M.

A solution has a molarity of 3.00 M and contains 4.50 moles of KNO₃. What is the volume of the solution in liters?

Answer explanation

To find the volume, use the formula: Molarity (M) = Moles of solute / Volume (L). Rearranging gives Volume = Moles / Molarity. Thus, Volume = 4.50 moles / 3.00 M = 1.50 L.

How many moles of NaOH are present in 0.50 L of a 1.5 M solution?

Answer explanation

To find moles, use the formula: moles = molarity × volume. Here, moles = 1.5 M × 0.50 L = 0.75 moles. Thus, there are 0.75 moles of NaOH in the solution.

A student dissolves 2.00 moles of sugar in enough water to make 1.25 L of solution. What is the molarity?

Answer explanation

Molarity (M) is calculated as moles of solute divided by liters of solution. Here, M = 2.00 moles / 1.25 L = 1.60 M. Thus, the molarity of the solution is 1.60 M.

How many liters of solution are needed to make a 2.0 M solution using 6.0 moles of solute?

Answer explanation

To find the volume of a 2.0 M solution using 6.0 moles of solute, use the formula: Molarity (M) = moles of solute / liters of solution. Rearranging gives liters = moles / M. Thus, liters = 6.0 moles / 2.0 M = 3.0 liters.

A 1.0 L solution contains 0.20 moles of MgCl₂. What is its molarity?

Answer explanation

Molarity (M) is calculated as moles of solute per liter of solution. Here, M = 0.20 moles / 1.0 L = 0.20 M. Therefore, the molarity of the MgCl₂ solution is 0.20 M.

Tags

NGSS.HS-PS1-5

What is the molarity of a solution if 0.040 moles of acetic acid (CH₃COOH) are dissolved in 0.080 L of water?

Answer explanation

Molarity (M) is calculated as moles of solute divided by liters of solution. Here, M = 0.040 moles / 0.080 L = 0.50 M. Thus, the molarity of the acetic acid solution is 0.50 M.

You have 1.2 liters of a 0.50 M H₂SO₄ solution. How many moles of H₂SO₄ are present?

Answer explanation

To find moles of H₂SO₄, use the formula: moles = molarity × volume. Here, moles = 0.50 M × 1.2 L = 0.60 moles. Thus, there are 0.60 moles of H₂SO₄ present.

How much solute (in moles) is required to make 3.5 L of a 0.80 M NaNO₃ solution?

Answer explanation

To find the moles of solute, use the formula: moles = molarity × volume. Here, moles = 0.80 M × 3.5 L = 2.8 moles. Therefore, 2.8 moles of NaNO₃ are required.