Test Review: Law of Conservation of Mass

EXPERIMENT #1

REACTANT(S) ------> PRODUCT(S)

48.6g Magnesium + 32.0g Oxygen ------> 80.6g Magnesium Oxide.

Does this experimental data support the Law of Conservation of Mass?

• yes

• no

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

EXPERIMENT #2

REACTANT(S) ------> PRODUCT(S)

____g Magnesium + 16.0g Oxygen ------> 40.3g Magnesium Oxide

a. Based on the Law of Conservation of Mass, predict the minimum amount of magnesium that will react with all 16.0 grams of oxygen to produce 40.3 grams of

magnesium oxide. _________________

• 40.3g

• 16.0g

• 24.3 g

• 56.3

Tags

NGSS.MS-PS1-5

EXPERIMENT #4

If the cap had been removed during the reaction (open system), would there still be 44g of Product in the jar?

• No, some of the substance was lost out of the container as a gas

• Yes, mass can't be destroyed

Tags

NGSS.MS-PS1-5

A scientist mixes 25 grams of Reactants, how many grams of products should I have (in a closed system)?

• 25g

• 50g

• 10g

• 15g

Tags

NGSS.MS-PS1-5

A scientist mixed 100 grams of salt into a 500 grams of water. How many grams of salt water did I make?

• 500g

• 400g

• 600g

• 700g

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

A chemical reaction is balanced when

• both sides have the same elements
• Both sides have the same  number of atoms
• Same subscripts
• Same coefficients

Tags

NGSS.MS-PS1-5

The coefficient in  3H₂O is

• 6
• 2
• 3
• 5

Tags

NGSS.MS-PS1-1