How concentrated is it? Comparing solutions

Answer Key - Grade 8 Science Worksheet - Challenge Me

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

1. 1.

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

   250 mL
2. 2.

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

   80 mL
3. 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?

   200 mL
4. 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. 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. 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. 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. 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. 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. 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