What makes an acid or a base

Answer Key - Grade 10 Science Worksheet - Building Confidence

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

1. 1.

   Each sulfuric acid molecule, H₂SO₄, can give up 2 H⁺ ions. How many H⁺ ions can 5 molecules give up, Ari?

   10 ions
2. 2.

   Each citric acid molecule in lemon juice can give up 3 H⁺ ions. How many H⁺ ions can 4 molecules give up, Bo?

   12 ions
3. 3.

   Each Mg(OH)₂ unit that dissolves from milk of magnesia releases 2 OH⁻ ions. How many OH⁻ ions do 7 units release, Esme?

   14 ions
5. 4.

   Using the strip, which liquid has more H⁺ than OH⁻, Kira?

   • Pure water
   • Baking soda solution
   • Vinegar
6. 5.

   Using the strip, why is pure water neutral, Luz?

   Use the picture in question 4.

   • It contains no ions
   • Its H⁺ and OH⁻ are equal
   • It has more OH⁻ than H⁺ ions
7. 6.

   What does an Arrhenius acid do in water, Milo?

   • Turns the water solid
   • Makes OH⁻ ions
   • Makes H⁺ ions
8. 7.

   What does an Arrhenius base do in water, Noah?

   • Makes H⁺ ions
   • Makes the water salty
   • Makes OH⁻ ions
9. 8.

   NaOH dissolves to give Na⁺ and OH⁻ ions. What is NaOH, Pia?

   • Neither one
   • An Arrhenius base
   • An Arrhenius acid
10. 9.

    Lemon juice has a pH of about 2.2. Is it acidic or basic, Ren?

    • Basic: its pH is below 7
    • Acidic: its pH is below 7
    • Neutral: it is a juice
11. 10.

    Baking soda solution has a pH of about 8.3. Is it acidic or basic, Tala?

    • Acidic: its pH is above 7
    • Neutral: it is a powder
    • Basic: its pH is above 7