Chemical Reactions & the Law of Conservation of Mass

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

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

The total amount of matter (atoms) before and after a chemical reaction remains the same.

• True
• False

Tags

NGSS.MS-PS1-5

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-PS1-2

NGSS.MS-PS1-5

Which picture below would correctly demonstrate the Law of Conservation of Matter if this picture is the reactants?

• 
• 
• 
• 

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What does the Law of Conservation of Mass state?

• Matter cannot be gained or lost in a chemical reaction.
• Matter can only be lost in a chemical reaction.
• Matter can only be gained in a chemical reaction.
• Matter can be gained and lost in a chemical reaction. 

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is the left part of a chemical equation called?
2H_{2 +} O₂ --> 2H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

Tags

NGSS.MS-PS1-5

What is the right part of a chemical equation called...
2H_{2 +} O₂ --> 2H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

Tags

NGSS.MS-PS1-5

Is ths a chemical or a physical change?

• Chemical change
• Physical change

Tags

NGSS.MS-PS1-2