8th grade Mass stays the same in a reaction worksheet

Mass stays the same in a reaction

Grade 8 Science Worksheet - Challenge Me

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

1. 1.

   In a teacher's sealed flask, 84 g of baking soda reacts with 60 g of the acid in vinegar. Sodium acetate and water total 100 g. What mass of carbon dioxide formed, Ari?
2. 2.

   A stove flame joins 16 g of methane with 64 g of oxygen. It makes 44 g of carbon dioxide and some water. What mass of water forms, Bo?
3. 3.

   In Esme's cells, 180 g of glucose and 192 g of oxygen can release energy, making 264 g of carbon dioxide and some water. What mass of water?
4. 4.

   Jun's mass graph is flat at 500 g, falls to 492 g, then levels off. Which story fits the graph?

   • A tablet fizzed in an open flask until it stopped
   • Mass was destroyed while the tablet fizzed
   • Water was poured in at 2 min
   • A sealed flask leaked air in
5. 5.

   Kira's mass graph rises slowly from 200 g to 206 g over 6 days. Which story fits the graph?

   • Steel wool rusted in a sealed jar
   • Rust made new matter from nothing
   • Water evaporated from the dish
   • Steel wool rusted in an open dish
6. 6.

   Luz's mass graph stays flat at 350 g while the liquid changes color. Which story fits the graph?

   • A gas escaped from an open flask
   • Mass was made and destroyed in equal amounts
   • No reaction, since the mass stayed the same
   • A reaction ran in a sealed flask
7. 7.

   A teacher lights a candle under a sealed glass jar on a scale. Milo predicts the reading. What happens to it?

   • It drops: the smoke weighs nothing
   • It doubles
   • It drops: burning destroys wax
   • It stays the same
8. 8.

   Steel wool sits in an open dish on a scale for a week and rusts. What does Pia predict for the reading?

   • It stays the same: mass is conserved
   • It drops: rusting wears away iron
   • It drops to 0 g
   • It rises as oxygen joins
9. 9.

   Tala says a burned log proves that burning destroys mass. Agree or disagree?

   • Disagree: ash is heavier than the log
   • Disagree: the mass left as gases
   • Agree: the ash is lighter, so mass was destroyed
   • Agree: fire uses up matter
10. 10.

    Zee says that since mass is conserved, an open cup's reading can't change while a tablet fizzes. Agree or disagree?

    • Disagree: escaping gas lowers the reading
    • Disagree: the reading rises
    • Agree: conserved means the reading stays put
    • Agree: no reaction changes a reading