Conservation of Mass & Matter Review

For the chemical reaction below, fill in the blanks with the correct number of molecules: 2 AgI + Na₂S → Ag₂S + 2 NaI. In the reaction there are ________ molecules of silver iodide (AgI) and ________ molecule(s) of sodium sulfide (Na₂S) that react to yield ____________ molecule(s) of silver sulfide (Ag₂S) and __________ molecules of sodium iodide.

(a)  

Tags

NGSS.MS-PS1-5

4 FeS + 7 O₂ → 2 Fe₂O₃ + 4 SO₂

How many molecules of FeS are in the reactants?

• 7

• 1

• 2

• 4

How many oxygen atoms are needed to make 1 molecule of O₂?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-1

4 FeS + 7 O₂ → 2 Fe₂O₃ + 4 SO₂

How many molecules of SO₂ are in the products?

• 1

• 4

• 2

• 7

One molecule of Fe₂O₃ has __________ atoms of iron (Fe) and ________ atoms of oxygen (O).

(a)  

Tags

NGSS.MS-PS1-1

What happened to the atoms during the chemical reaction to cause this change?

• The atoms were rearranged to form new substances.

• The atoms disappeared completely.

• The atoms changed into energy.

• The atoms remained unchanged.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

C₂H₆O + 3O₂ → CO₂ + 3H₂O

Is mass conserved in this reaction?

• Yes, mass is conserved in the reaction.

• No, mass is not conserved in the reaction.

Tags

NGSS.MS-PS1-5

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

How many molecules of CO₂ are in the reactants?

• 0

• 1

• 2

• 6

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

How many atoms of Oxygen are in the products?

• 6

• 2

• 12

• 18

Tags

NGSS.MS-PS1-1