Conservation of Mass

In a chemical reaction, the mass of the reactants was 15g.  The mass of the products was 12g.  Did this chemical reaction follow the law of conservation of mass?

• Yes 
• No
• You can't tell with the given infomation 

There are two reactants in a chemical equation, and one product.  The mass of the product is 30g.  The mass of the first reactant is 17g.  What must the mass of the second reactant be, if the equation is to follow the law of conservation of mass?

• 47g
• 13g
• 23g 
• You cant tell with the given information

Tags

NGSS.MS-PS1-5

Which of the following is a chemical change?

• Baking soda and vinegar producing gas bubbles
• A chocolate bar melting
• Powdered lemonade dissolving in water
• Frosting a cake

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The substances listed to the left of the arrow in a chemical reaction are called the _______________.

• products
• reactants
• substances
• materials

Which of the following is true of the law of conservation of mass?

• The same number and type of each atom will always be present before and after a chemical reaction takes place.
• Some of the atoms present before the reaction will always be lost during a chemical reaction.
• Some of the atoms will always be changed into a different type of atom by a chemical reaction.
• During a chemical reaction, atoms will always be combined into much larger molecules.

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-PS1-2

NGSS.MS-PS1-5

Is this equation balanced?

• yes
• no
• Not enough information

Tags

NGSS.MS-PS1-5

Is this equation balanced?

• yes
• no
• Not enough information

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Can matter be created or destroyed?

• Yes, it can be created.
• Yes, it can be destroyed.
• No, matter is always conserved
• None of these

Tags

NGSS.MS-PS1-5

If 10 grams of water are added to 5 grams of salt, how much salt water will be made?

• 2 grams
• 5 grams
• 10 grams
• 15 grams

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5