Law of Conservation of Matter

In a reaction A + B ----> C,  reactant A has 5g and product  C has 9g. How many grams does reactant B should have? 

• 4g
• 5g
• 9g
• 14g

Tags

NGSS.MS-PS1-5

Bob puts 200 grams of ice into a pitcher with 900 grams of water. He gets distracted and comes back later to find that the ice has melted in the water. How many grams of water does Bob now have in the pitcher?

• 200 g
• 700 g
• 1,100 g

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-4

24 g of magnesium reacts with 38 g of fluorine to produce _____ g magnesium fluoride

• 62 
• 38
• 24
• 14

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

What is the law of conservation of mass?

• The amount of matter changes when reacted or changed.
• The mass of all reactants are changed during a physical or chemical change
• The mass of the reactants equals the mass of the products
• The mass of the products is different than the mass of the reactants.

Tags

NGSS.MS-PS1-5

Students react baking soda & vinegar.
Which of the following would provide the evidence that the number of atoms present before a chemical reaction is equal to the number of atoms present after the chemical reaction?

• The mass of the plastic bag, baking soda, and vinegar before the reaction was equal to the mass after the reaction.
• Bubbles were produced during the reaction, which meant that a gas was being produced.
• The plastic bag did not change in any way, indicating that it was not involved in the reaction.
• The mass of the baking soda was exactly equal to the mass of the vinegar used to create the chemical reaction.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

The Law of Conservation of matter states that the total amount of matter ______________ after it undergoes change.

• disappears
• stays the same
• weighs less
• explodes

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

What is the part of the chemical equation in green called?

Fe + S → FeS

• products

• reactants

• yield

• input

What is the right part of a chemical equation called...

2H_{2 +} O₂ --> 2H₂O

• Reactants

• Products

• Yields

• Output

This type of system allows matter to flow freely in and out...

• Closed System

• Open System

Tags

NGSS.MS-PS1-4

NGSS.MS-LS2-3

A boiling pot with a lid on it to keep in the energy is what type of system?

• Closed System
• Open System

Tags

NGSS.HS-PS3-4