Conservation of Mass
Counting Atoms & Molecules
Balanced Equations
Reaction Scenarios
Random
100
Matter cannot be ______________ during a chemical reaction.
a) B and C
B) destroyed
C) created
D) changed
a) B and C
100
How many total atoms of Chlorine are there in 2NaCl2 ?
4
100
If a chemical reaction begins with 6 atoms of carbon (C), how many atoms of carbon (C) should be in the products?
6 atoms of Carbon (C)
100
Jackie and Josh measured 35g before and 33g after mixing baking soda and vinegar. What explains the missing mass?
a) Gas was released and not captured
100
My Science teacher is
Ms. Rosales
200
The total mass of the products of a chemical reaction _______ the total mass of the reactants.
is the same as
200
Which chemical equation supports the Law of Conservation of Mass?
a) 2Al + 3HCl → 2AlCl₃ + 3H₂
b) SO₂ + O₂ → S₂O₅
c) 4P + 4O₂ → 2P₂O₅
d) 2H₂O → 2H₂ + O₂
d) 2H₂O → 2H₂ + O₂
200
What number represents a coefficient in the products in this equation: Cl₂ + Na → 3ClNa?
3
200
What is the importance of a closed container in a chemical reaction?
to observe the mass before and after the reaction occurs
200
What is the capital city of France?
Paris
300
How does a balanced chemical equation satisfy the Law of Conservation of Mass?
During a chemical reaction, the total amount of matter stays the same
300
3P + 5O₂ → P₂O₅. Is it balanced?
balanced or unbalanced?
explain why?
unbalanced
300
Which equation is balanced according to the Law of Conservation of Mass?
a) 2NaCl + Mg → MgCl₂ + Na
b) 2NaCl + Mg → MgCl + 2Na
c) NaCl + Mg → MgCl + Na
c) NaCl + Mg → MgCl + Na
300
A 10g aluminum can reacts with 100g hydrochloric acid (total mass 110g) , after the reaction the mass was 108g. What explains the missing 2g?
Mass lost as gas
300
What color do you get when you mix red and blue?
Purple
400
Which best explains why the total mass of the product(s) would be less than the total weight of the reactant(s) after a chemical reaction?
a) Atoms involved in the reaction lost mass.
b) Precipitates were created in the new solution.
c) A physical change occurred.
d) Gases were released to the atmosphere.
d) gases were released to the atmosphere
400
Which equation supports this model?
a) 2H2O2 → 2H2O b) 2H2 + O2 → H2O
c) 2H2 + O2 → 2H2O d) H2 + O2 → 2H2O
c) 2H2 + O2 → 2H2O
400
If a chemical equation is not balanced, what does that mean about the law of Conservation of Mass?
The number of atoms on both sides is not equal, so mass is not conserved
400
When you bake bread, yeast makes gas that make the dough rise. Why does the dough's weight stay about the same?
The dough is in a closed oven, so nothing escapes.
400
How many colors are in a rainbow?
7
500
When vinegar and baking soda are combined, a mixture is produced, and gas is released. Which statement is true?
a) The mass of the gas is equal to the mass of the vinegar and baking soda
b) The mass of the mixture and gas is greater than the mass of the baking soda and vinegar
c) The mass of the mixture and gas is equal to the mass of the vinegar and baking soda
a) The mass of the gas is equal to the mass of the vinegar and baking soda
500
According to the Law of Conservation of Mass, what will be the mass of Zinc after the reaction has taken place?
104 g
500
Why is it important for a chemical equation to be balanced?
To show the same number of atoms on both sides, obeying the law of conservation of Mass
500
Fireworks explode in the sky making light and gas. Why might the weigh of the fireworks before and after the explosion be different if measured outside?
Some gas and smoke float away into the air
500
Who painted the Mona Lisa?
Leonardo da Vinci