Law of Conservation of Mass

What is the Law of Conservation of mass?

• Mass is created in a chemical reaction
• Mass is created in a physical change
• New chemicals formed from a chemical reaction have a larger overall mass than the original reactants
• Mass is never created or destroyed

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

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

If a reaction starts with a total 75g of reactants it should produce 

• a total of 40g of products
• a total of 75g of products
• a total of 180 g of products
• None of the above

Tags

NGSS.MS-PS1-5

In the reaction AB-----> A + B reactant AB has 12g and product B has 5g. How many grams should product A have?

• 17g
• 2g
• 7g
• None of the above

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

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-PS1-4

Which of these is not a chemical reaction?

• Burning of wood
• Milk going bad
• Mixing vinegar and baking soda
• Melting of ice

Tags

NGSS.MS-PS1-2

What will weigh more when a chemical change is complete?  The reactants before the chemical reaction, or the product after the reaction is complete?

• They both will weigh the same
• The product always weighs more than the reactant
• The reactant will weigh more than the product
• They both will loose mass after the reaction

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Since gasses weigh nothing, when they are produced in a reaction they do not have to be accounted for.  

• True
• False

Tags

NGSS.MS-PS1-5

12g of Carbon react with 16g of Oxygen, how much carbon monoxide (CO) is formed? 

• 28 g
• 4g
• 30g
• 12g

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

In the reaction shown by the equation, 252 grams of FeCl₂ and 70 grams of Cl₂ are consumed.
2FeCl₂+ Cl₂--> 2FeCl₃ 
How many grams of FeCl₃ are produced? 

• 161 grams
• 182 grams
• 322 grams
• 392 grams

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2