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Topic 4: Modeling Conservation of Mass

Total questions: 34

Worksheet time: 22mins

Name
Class
Date
1.

There are 2 g worth of products in a chemical reaction. How many were needed in the reactant stage

a)

2 g

b)

13 g

c)

6.5 g

d)

8 g

2.

What does Law of Conservation say about matter

a)

That the amount of matter changes in a chemical reaction.

b)

That the amount of matter doubles in a chemical reaction.

c)

That the amount of matter stays the same in a chemical reaction.

d)

That the amount of matter halves in a chemical reaction.

3.

What happens to the number of atoms as it goes through a chemical reaction

a)

Doubles

b)

Changes

c)

Stays the same

4.

When a reaction produces a gas, does the reaction overall lose mass

a)

No the mass is still in the solid

b)

No the mass is conserved in the gas

c)

Yes the mass will go down when the gas leaves

d)

Yes the mass will go up when the gas leaves

5.

If 45g of reactants go through a reaction how much product will be produced?

a)

20g

b)

15g

c)

35g

d)

45g

6.

In this chemical equation , CH4 and 2O2 are called the...

a)

Products

b)

Reactants

c)

Coefficient

d)

Subscript

7.

In this chemical equation , CO2 and 2H2O are called the...

a)

Products

b)

Reactants

c)

Coefficient

d)

Subscript

8.

In this chemical equation , the 2 in front of the 2O2 and the 2 in front of the 2H2O are called the...

a)

Products

b)

Reactants

c)

Coefficient

d)

Subscript

9.

In this chemical equation ,the small numbers dropped down below the letters like the 4 in CH4 are known as the

a)

Products

b)

Reactants

c)

Coefficient

d)

Subscript

10.

If you have 15 grams of Baking Soda and 20 grams of Vinegar as products, what would you expect the mass of your reactants to be?

a)

15 grams

b)

20 grams

c)

5 grams

d)

35 grams

11.

Looking at the products , there is _____ atom(s) of Oxygen in CO2 and _______ atom(s) of Oxygen in 2H2O.

a)

1, 1

b)

1, 2

c)

2, 2

d)

2, 4

12.

Looking at the reactants, there is _____ molecule(s) of CH4 and _______ molecule(s) of O2.

a)

1, 1

b)

1, 2

c)

2, 2

d)

2, 4

13.
Fill in the blank:
A __________________ chemical equation shows that the same number of atoms in the reactants are also in the product.
a)
balanced
b)
transferred
c)
rearranged
d)
beautiful
14.
Fill in the blank:
It is best to observe the law of conservation of mass in a _____________________ system because it will ensure that the mass is the same in the beginning and end of a chemical reaction.
a)
closed
b)
open
c)
balanced
d)
rearranged
15.
The following chemical reaction occurs:
2S + 3O2 -> 2SO3
How many atoms of oxygen are there in the reactant?
a)
2 atoms of oxygen
b)
3 atoms of oxygen
c)
6 atoms of oxygen
d)
1 atom of oxygen
16.
The following chemical equation occurs:
CH4 + 2O2 -> CO2 + 2H2O
Does this equation follow the law of conservation of mass?  In other words, are there the same number of carbon, hydrogen, and oxygen atoms in the reactants and the products?
a)
Yes
b)
No
c)
You can't tell with the given information 
17.
Is this equation balanced?
a)
yes
b)
no
c)
Not enough information
18.
Is this equation balanced?
a)
yes
b)
no
c)
Not enough information
19.

Which chemical equation is balanced:

a)

CH4 + O2 → CO2 + H2O

b)

CH4 + 2O2 → 2CO2 + H2O

c)

CH4 + 2O2 → CO2 + 2H2O

d)

2CH4 + O2 → CO2 + 2H2O

20.

In a chemical reaction,

a)

the atoms of the reactants always stay together.

b)

the atoms of the reactants rearrange, to form new products.

c)

new atoms are formed when combined to make the products

d)

some atoms disappear & others multiply to form products

21.

How many elements are in C6H12O6?

a)

1

b)

2

c)

3

d)

4

22.

Determined whether the following equation is balanced or unbalanced. Ag + O2 ---> 2Ag2O

a)

Balanced

b)

Unbalanced

23.

Determine whether the following equation is balanced or unbalanced. 4P +5O2 ---> 2P2O5

a)

Balanced

b)

Unbalanced

24.

Determine whether the following equation is balanced or unbalanced. H2 + Br2 ---> 2HBr

a)

Balanced

b)

Unbalanced

25.

Determine whether the following equation is balanced or unbalanced. 2Fe + 3Cl2 ---> FeCl3

a)

Balanced

b)

Unbalanced

26.

In order for an equation to be balanced, there must be ...

a)

an equal amount of atoms on both sides

b)

a greater mass on the product side

c)

a greater mass on the reactant side

d)

elements with the same atomic # on both sides

27.

Which of the following equations is balanced?

a)

P4 + 3O2 ---> 2P2O3

b)

N4 + 3F2 ---> 2NF3

c)

2LiF + Br2 ---> 2LiBr + F4

28.

How many of each type of atom are in 4NO2?

a)

4 nitrogen, 2 oxygen

b)

4 nitrogen, 6 oxygen

c)

4 nitrogen, 8 oxygen

d)

8 nobelium

29.

A reaction occurs between two liquid substances in a sealed jar. What will happen to the mass of the sealed jar and its contents after the reaction occurs?

a)

The mass will change if a gas is formed, and it will change if a solid is formed.

b)

The mass will change if a gas is formed, but it will not change if a solid is formed.

c)

The mass will change if a solid is formed, but it will not change if a gas is formed.

d)

The mass will not change if a gas is formed, and it will not change if a solid is formed.

30.

A student places some baking soda and a jar of lemon juice in a plastic bag and seals the bag. They weigh the bag and everything in it. They shake the bag so that the lemon juice spills out of the jar and mixes with the baking soda inside the bag. The student observes that bubbles form and the bag expands. If the student weighs the bag and everything in it after the bubbling stops and compares the final weight to the starting weight, what will they find out?

a)

The final weight will be greater than the starting weight because new atoms are produced during the experiment.

b)

The final weight will be less than the starting weight because some of the atoms are destroyed during the experiment.

c)

The final weight will be the same as the starting weight because the number of each kind of atom does not change during the experiment.

d)

The final weight will be the same as the starting weight because some atoms are destroyed, but new ones are created during the experiment.

31.

Two white powders were mixed together. A chemical reaction occurred, and a yellow powder was formed. What is the relationship between the yellow powder and the white powders?

a)

The yellow powder is made up of the same kinds of atoms as the white powders, but the atoms are combined into different molecules.

b)

The yellow powder is made up of the same kinds of molecules as the white powders, but the molecules are a different color.

c)

The yellow powder was released from inside the atoms of the white powders.

d)

There is no relationship between the yellow powder and white powders.

32.

Atoms are represented by circles, and molecules are represented by circles that are connected to each other. The different colored circles represent different kinds of atoms. Which of the following could represent a chemical reaction?

a)
b)
c)
d)
33.

To prevent the loss of something

a)

Chemical reaction

b)

Mass

c)

Atom

d)

Conserve

34.

When the number of each reactant's atoms and the number of each product's atoms are equal, the chemical reaction is [BLANK]

a)

Balanced

b)

Mass

c)

Destroyed

d)

Coefficient