Chemical Reactions (Types, Cons of Mass and Balancing) Review

What does the principle of conservation of mass mean?

• The total mass of the reactants is more than the products
• Matter is not created or destroyed
• The total mass of the reactants is less than the products

Tags

NGSS.HS-PS1-7

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.HS-PS1-7

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-PS1-5

If there are 4 H atoms on the reactant side, how many H atoms will be on the product side? 

• 2
• 4
• 6
• You need more information to answer this question

Tags

NGSS.HS-PS1-7

What is the part of the chemical equation in green called?

Fe + S → FeS

• products

• reactants

• yield

• input

What is the right part of a chemical equation called...

2H_{2 +} O₂ --> 2H₂O

• Reactants

• Products

• Yields

• Output

Which is Chemical Equation is Balanced?

• CH₄+O₂------CO₂+2H₂O
• H₂+O₂-----2H₂O₄
• 4Al+3O₂-----2Al₂O₃

Tags

NGSS.HS-PS1-7

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

• balanced
• unbalanced

Tags

NGSS.HS-PS1-7

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

• 62 
• 38
• 24
• 14

Tags

NGSS.HS-PS1-7

Balance this equation.
_CF₄ + _Br₂ -- _CBr₄ + _F₂

• 2,1,2,1
• 1,2,2,1
• 1,2,1,2
• 2,2,2,2