Dilution calculations

Answer Key - Grade 10 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   0.1 L of 2 M salt water is diluted to 0.5 L. What is the new molarity, to 0.01 M, Ari?

   0.4 M
2. 2.

   0.05 L of 1 M sugar water is diluted to 0.2 L. What is the new molarity, to 0.01 M, Bo?

   0.25 M
3. 3.

   0.2 L of 3 M salt water is diluted to 1.2 L. What is the new molarity, to 0.01 M, Kira?

   0.5 M
4. 4.

   Adding water to salt water does what to the moles of salt, Jun?

   • It removes some of the salt's moles
   • It adds moles of salt along with the new water
   • Nothing: the moles of salt stay the same
5. 5.

   Adding water to sugar water does what to its molarity, Luz?

   • It raises it, since the extra water adds sugar moles
   • It stays the same, since the sugar is the same
   • It lowers it, since the same moles fill more liters
6. 6.

   Why is M₁V₁ = M₂V₂ true for a dilution, Milo?

   • Adding water adds solute moles, keeping both sides even
   • Both sides equal the moles of solute
   • Both sides equal the liters of water added to it
7. 7.

   What does diluting a solution mean, Ren?

   • Adding solute so the concentration rises
   • Heating it until some of the water boils off
   • Adding solvent so the concentration drops
8. 8.

   Which setup finds M₂ after diluting 0.10 L of 2.0 M to 0.50 L, Tala?

   • M₂ = 2.0 ÷ 0.10 × 0.50
   • M₂ = 2.0 × 0.10 ÷ 0.50
   • M₂ = 2.0 × 0.50 ÷ 0.10
9. 9.

   Which setup finds V₂ when 0.40 L of 1.5 M is diluted to 0.50 M, Zee?

   • V₂ = 1.5 × 0.40 ÷ 0.50
   • V₂ = 1.5 × 0.50 ÷ 0.40
   • V₂ = 0.50 × 0.40 ÷ 1.5
10. 10.

    In M₁V₁ = M₂V₂, what does V₂ stand for, Esme?

    • The final volume of the diluted solution
    • The starting volume before any water
    • The volume of water added to the solution