8th Law of Mass Quiz

Lucy mixed soy sauce, rice vinegar, and sesame oil together in a bottle to make 450 grams of sauce. She put the bottle of sauce in her kitchen cabinet.

A week later, Lucy took the bottle out of her cabinet and saw that there had been a change. The sesame oil had separated from the soy sauce and rice vinegar.

There were 400 grams of the soy sauce and rice vinegar mixture. There was also some sesame oil floating on top.

Complete the bar graph to show the mass of the sesame oil.

Steven had an 800-gram ball of wet clay. He rolled out the clay to make a thin, flat plate.

Overnight, there was a change. Some of the water from the clay evaporated and formed water vapor. The next day, Steven's plate was hard and dry. It had a mass of 600 grams.

Complete the bar graph to show the mass of the water vapor.

Franklin boiled some pasta. He put 500 grams of water into a pot and heated it on the stove. When the water started to boil, he added 100 grams of uncooked pasta for a total of 600 grams.

Ten minutes later, Franklin saw that his pasta had cooked. The cooked pasta had a mass of 150 grams. Fifty grams of water had vaporized, and there was some water left in the pot.

Which statement explains the change in mass?

• There was some water in the uncooked pasta, and that water evaporated. The cooked pasta did not contain water

• While the pasta cooked, it absorbed some water. So, the pasta gained mass

• The pasta heated up while it cooked. Because it gained heat energy, it gained mass

Before the change, the total mass of the jello powder and warm water was (a)   grams.

How many atoms of each element are in the reaction?

• H=6

  N=18

• H=2

  N=9

• H=18

  N=6

• H=9

  N=2

How many atoms of hydrogen are in the products?

• 1

• 2

• 3

• 4

What is the law of conservation of mass?

• atoms are not created, but destroyed.

• atoms cannot be rearranged in chemical reactions

• atoms are not created or destroyed in chemical reactions

• atoms are always created in chemical reactions

If 50g of Calcium reacts with 22g of Oxygen, what will the mass of the products be?

• 72g

• 50g

• 22g

• 0g

What is the mass of 0₂?

• 192g

• 64g

• 256g

• 400g

14g of Li reacts with 32g of S to produce __g of Li₂S

• 46g

• 14g

• 32g

• 18g