PencilGo

Grade 8 · Science

8th grade How concentrated is it? Comparing solutions worksheet

6 printable versionsChallenge Me10 questions · answer keyFree · no account

Level: Building Confidence · On Level · Challenge Me

When it’s done, scan the sheet with your phone and PencilGo marks it and picks the next one. Create a free account

Version
Print

How concentrated is it? Comparing solutions

Grade 8 Science Worksheet - Challenge Me

NameDate

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

  1. Beaker A has 40 dots in 150 mL. Ari wants 10 dots per 100 mL. How many mL of water must be added?

  2. Beaker B has 30 dots in 120 mL. Bo wants 15 dots per 100 mL. How many mL of water must be added?

  3. Esme's beaker has 60 dots in 300 mL. To reach 12 dots per 100 mL, how many mL of water must be added?

  4. Kira mixes 100 mL with 4 dots per 100 mL and 100 mL with 8 dots per 100 mL. What is the mix's concentration?

    • 8 dots per 100 mL
    • 12 dots per 100 mL
    • 4 dots per 100 mL
    • 6 dots per 100 mL
  5. Luz mixes a strong solution with a weak one. Where does the mix's concentration land?

    • Above the stronger one
    • Exactly at zero
    • Between the two
    • Below the weaker one
  6. Milo says a big pot of soup must be saltier than a small bowl, because it holds more salt. Agree or disagree?

    • Disagree: compare salt per 100 mL
    • Disagree: soup has no salt
    • Agree: a bigger pot is stronger
    • Agree: more salt means saltier
  7. Noah says pouring half a glass of sugar water away makes the rest twice as concentrated. Agree or disagree?

    • Disagree: it stays the same
    • Agree: less water means stronger
    • Disagree: it becomes pure water
    • Agree: half the sugar is left, so weaker
  8. Ren wants 300 mL with the same strength as 100 mL holding 4 dots. How many dots are needed?

    • 12 dots
    • 4 dots
    • 1 dot
    • 7 dots
  9. Two beakers each have 6 dots per 100 mL. Tala mixes them. Which drawing shows the mix?

    • 18 dots in 100 mL
    • 6 dots in 300 mL
    • 12 dots in 300 mL
    • 18 dots in 300 mL
  10. Zee mixes 200 mL at 3 dots per 100 mL with 200 mL at 9 dots per 100 mL. What is the mix's concentration?

    • 6 dots per 100 mL
    • 12 dots per 100 mL
    • 9 dots per 100 mL
    • 3 dots per 100 mL
PencilGopencilgo.com

8th grade How concentrated is it? Comparing solutions worksheet – printable
Print: 123456

About this worksheet

How concentrated is it? Comparing solutions. Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

  • I can compare solutions by the amount dissolved in each 100 mL, not by the total or by the volume alone.
  • I can say what adding water, adding solute, pouring off half or evaporating water does to concentration.
  • I can work out how much water to add for a target strength, and what strength a mix of two solutions has.

Standard: none (IXL parity)

Words to know

solution: A mixture where one substance is dissolved evenly in another

solute: The substance that dissolves, like sugar

solvent: The liquid it dissolves in, like water

concentration: How much solute is dissolved in a set amount of solution

dilute: Having little solute in each 100 mL

concentrated: Having a lot of solute in each 100 mL

Common mistakes

Your child gave the total number of dots instead of the dots in each 100 mL. Split the liquid into 100 mL parts and share the dots out.

Your child multiplied the amount by the volume. To find how much is in each 100 mL, divide the amount by the number of 100 mL parts.

Your child compared only how much was dissolved, not how much liquid it was in. Concentration is the amount for each 100 mL.

Questions parents ask

What is the most common mistake with how concentrated is it? comparing solutions?

Your child gave the total number of dots instead of the dots in each 100 mL. Split the liquid into 100 mL parts and share the dots out.

Are these 8th grade science worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

More grade 8 science

See all grade 8 science

Every sheet you scan goes into your child’s record: dated, marked and ready for the year-end portfolio. Homeschool records