What makes an acid or a base

Answer Key - Grade 10 Science Worksheet

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

1. 1.

   Acetic acid, CH₃COOH, has 4 hydrogen atoms and gives up one H⁺. How many hydrogen atoms does its conjugate base have, Ari?

   3 H atoms
2. 2.

   Citric acid, C₆H₈O₇, has 8 hydrogen atoms and gives up one H⁺. How many hydrogen atoms does its first conjugate base have, Bo?

   7 H atoms
3. 3.

   Sulfuric acid, H₂SO₄, has 2 hydrogen atoms and gives up one H⁺. How many hydrogen atoms does HSO₄⁻, its conjugate base, have, Esme?

   1 H atoms
4. 4.

   In NH₃ + H₂O → NH₄⁺ + OH⁻, what does water do, Luz?

   • Hands NH₃ a whole OH⁻ ion
   • Accepts a proton from NH₃
   • Donates a proton to NH₃
5. 5.

   What is the conjugate base of acetic acid, CH₃COOH, Milo?

   • OH⁻
   • CH₃COOH₂⁺
   • CH₃COO⁻
6. 6.

   What is the conjugate acid of ammonia, NH₃, Noah?

   • NH₄⁺
   • H₃O⁺
   • NH₂⁻
7. 7.

   In HCl + H₂O → H₃O⁺ + Cl⁻, which two form a conjugate acid-base pair, Pia?

   • Cl⁻ and H₃O⁺
   • HCl and Cl⁻
   • HCl and H₂O
8. 8.

   Milk of magnesia is mostly Mg(OH)₂. Why does it count as an Arrhenius base, Ren?

   • It gives OH⁻ ions in water
   • It has no hydrogen atoms in it
   • Its Mg²⁺ ions donate protons
9. 9.

   Ammonia, NH₃, has no OH⁻ in its formula. Why is it still a base, Tala?

   • It donates a proton to water
   • It accepts a proton from water
   • It gives off H⁺ in water
10. 10.

    Which substance can act as an acid in one reaction and a base in another, Zee?

    • Hydrochloric acid
    • Sodium hydroxide
    • Water