Law of Conservation of Mass 2019

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-PS1-2

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

The number to the lower side of an element is a 

• Subscript

• Superscript

• Coefficient

• Charge

Tags

NGSS.MS-PS1-1

The number in front of a compound or element is a 

• Subscript

• Coefficient

• Superscript

• Charge

Which is Chemical Equation is Balanced?

• CH₄+O₂------CO₂+2H₂O

• H₂+O₂-----2H₂O₄

• 4Al+3O₂-----2Al₂O₃

Tags

NGSS.MS-PS1-5

Is this equation balanced or unbalanced? 
2Fe₂O₃ + 3C --> 4Fe + 3 CO₂

• balanced

• unbalanced

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

NGSS.MS-PS1-5