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

   80 mL
2. 2.

   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
3. 3.

   Jun pours two cups of lemonade together. Each has 5 g of sugar per 100 mL. What is the mix's concentration?

   • 0 g per 100 mL
   • 10 g per 100 mL
   • 5 g per 100 mL
   • 2.5 g per 100 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?

   • 12 dots per 100 mL
   • 4 dots per 100 mL
   • 8 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?

   • Exactly at zero
   • Below the weaker one
   • Above the stronger one
   • Between the two
6. 6.

   Milo says a big pot of soup must be saltier than a small bowl, because it holds more salt. Agree or disagree?

   • Agree: a bigger pot is stronger
   • Disagree: soup has no salt
   • Disagree: compare salt per 100 mL
   • 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: half the sugar is left, so weaker
   • Disagree: it becomes pure water
   • Agree: less water means stronger
8. 8.

   Beaker A has 9 dots in 300 mL and beaker B has 4 dots in 100 mL. Pia says A is more concentrated. Agree or disagree?

   • Agree: A has more liquid
   • Agree: A has more dots
   • Disagree: B has more per 100 mL
   • Disagree: they are the same
9. 9.

   Ren wants 300 mL with the same strength as 100 mL holding 4 dots. How many dots are needed?

   • 1 dot
   • 7 dots
   • 12 dots
   • 4 dots
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?

    • 9 dots per 100 mL
    • 3 dots per 100 mL
    • 12 dots per 100 mL
    • 6 dots per 100 mL