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-PS1-2

NGSS.MS-PS1-5

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

Matter can not be created nor destroyed: it can only be

• Destroyed a little bit
• Invisible
• Transformed, changed
• None of the above

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-PS1-2

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-PS1-4

When CaCO₃ is heated, it forms CaO and CO₂. Which of these statements best describes the mass of the products if 100 g of CaCO₃ is heated?

• The difference in the products’ masses is equal to the mass of the CaCO₃
• The sum of the products’ masses is less than the mass of the CaCO₃
• The mass of each product is equal to the mass of the CaCO₃
• The sum of the products’ masses equals the mass of the CaCO₃

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

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

• 62 
• 38
• 24
• 14

Tags

NGSS.MS-PS1-5

32 g of Oxygen completely reacts with 8 g of Hydrogen to produce _____ g Water

• 8

• 12

• 24

• 40

Tags

NGSS.MS-PS1-5