Find a concentration from a titration

Answer Key - Grade 10 Science Worksheet

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

1. 1.

   A described curve for 20 mL of HCl jumps at 25 mL of 0.1 M NaOH. HCl and NaOH react 1 : 1. What is the HCl concentration, Ari?

   0.125 M
2. 2.

   A described curve for 25 mL of HCl jumps at 18.5 mL of 0.12 M NaOH. HCl and NaOH react 1 : 1. What is the HCl concentration, Bo?

   0.089 M
3. 3.

   A described curve rises slowly, jumps steeply at 18.5 mL and then levels off near pH 12. Which volume gives the equivalence point, Jun?

   • 18.5 mL
   • The final volume
   • 0 mL
4. 4.

   Why is the pH low before the jump on a curve for HCl and NaOH, Kira?

   • Extra NaOH remains
   • No acid is present
   • Extra HCl remains
5. 5.

   Why is the pH near 12 after the jump, Luz?

   • Extra NaOH remains
   • Extra HCl remains
   • The salt is basic
6. 6.

   In HCl + NaOH → NaCl + H₂O, what is the mole ratio of acid to base, Milo?

   • 2 : 1
   • 1 : 2
   • 1 : 1
7. 7.

   At the equivalence point of HCl with NaOH, what equals the moles of HCl, Pia?

   • The moles of NaOH added
   • The volume of NaOH added
   • The pH of the mixture
8. 8.

   Which equation fits a 1 : 1 acid–base titration, Ren?

   • Ca × Vb = Cb × Va
   • Ca × Va = Cb × Vb
   • Ca + Va = Cb + Vb
9. 9.

   In Ca × Va = Cb × Vb, can both volumes stay in mL, Tala?

   • Yes: the units cancel
   • No: Va alone may be in mL
   • No: both must be in grams
10. 10.

    Two HCl samples of equal volume need 20 mL and 30 mL of the same NaOH. Which is more concentrated, Zee?

    • The one needing 30 mL
    • They are equal
    • The one needing 20 mL