WorksheetsEVIDENCE OF A CC, FORMULAS, & EQUATIONS
Total questions: 79
Worksheet time: 3hrs 47mins
Name
Class
Date
1.
Is the following equation balanced or unbalanced?
Fe + S --> FeS
Fe + S --> FeS
a)
balanced
b)
unbalanced
2.
How many atoms of aluminum are on each side of the following equation: 4Al + 3O2 --> 2Al2 O3
a)
2
b)
6
c)
1
d)
4
3.
When materials combine to form new compounds it is a chemical change. Which example is a chemical change?
a)
baking powder fizzing
b)
water boiling
c)
ice melting
d)
sugar cube dissolving
4.
Tearing paper is an example of
a)
physical change.
b)
chemical change.
c)
chemical reaction.
d)
solution.
5.
If you break a piece of glass, the shape of the glass changes, but the properties in the fragments remain the same. Which of the following has occurred?
a)
A chemical change.
b)
A temperature change.
c)
A phase change.
d)
A physical change.
6.
Which process is a physical change?
a)
Rusting iron
b)
Burning coal
c)
Tarnishing silver
d)
Melting ice
7.
Which of the following does not show a chemical change?
a)
change of state of matter
b)
color change
c)
production of a gas
d)
all show a chemical change
8.
Mark is observing a burning candle. He notices the melted wax drips down the side of the candle and hardens again. The candle has____.
a)
formed a new substance
b)
undergone a physical change
c)
undergone a chemical change
d)
undergone a physical and chemical change
9.
A chemical change creates a ______.
a)
change in volume
b)
new substance
c)
mixture
d)
solution
10.
A different chemical substance is formed when _____.
a)
water boils
b)
metal rusts
c)
ice melts
d)
rock is crushed
11.
A teacher is demonstrating physical and chemical changes to her class. Which action should she use to demonstrate a chemical change?
a)
cutting a piece of paper
b)
folding a piece of paper
c)
tearing a piece of paper
d)
burning a piece of paper
12.
A science teacher lit a candle and described to his students that some of the wax is burning while some of the wax is melting. Student A states that these are both physical changes. Students B states that these are both chemical changes. Which statement BEST describes the students' conclusions?
a)
Student A is correct.
b)
Student B is correct.
c)
Both are incorrect, because burning wax is a chemical change and melting wax is a physical change.
d)
Both are incorrect, because burning wax is a physical change and melting wax is a chemical change.
13.
A group of students investigated physical and chemical changes using paper. The students recorded their observations in a table.
Which student correctly recorded all the changes that took place?
Which student correctly recorded all the changes that took place?
a)
Student 1
b)
Student 2
c)
Student 3
d)
Student 4
14.
The smell made from a decomposing fish.
a)
Chemical Change
b)
Physical Change
15.
Green bananas turning yellow on their own as they ripen.
a)
Chemical Change
b)
Physical Change
16.
a copper penny turning greenish after a few years.
a)
Chemical Change
b)
Physical Change
17.
An gel ice pack getting cold after you put it in the freezer for an hour.
a)
Chemical Change
b)
Physical Change
18.
Melting an ice cube
a)
Chemical Change
b)
Physical Change
19.
Which is an example of a chemical reaction?
a)
paper cut into small pieces
b)
chocolate melting in a pan
c)
flour and sugar mixed in a bowl
d)
cookies baking in an oven
20.
Changes in which new substances are formed are called
a)
physical changes
b)
chemical changes
21.
Which of the following describes a precipitate?
a)
a liquid forms when a block of metal is heated
b)
a solid forms when one liquid is poured into another
c)
a gas forms when a solid is placed in a liquid
d)
bubbles form when an acid is poured on a rock
22.
Which is a physical change?
a)
digesting food
b)
burning natural gas
c)
exploding firework
d)
chopping onions
23.
Digesting your food is an example of
a)
chemical change
b)
physical change
24.
Dissolving sugar in water is an example of a
a)
physical change
b)
chemical change
25.
Photosynthesis is an example of a
a)
physical change
b)
chemical change
26.
Which of the following is NOT evidence that that a chemical reaction has occurred?
a)
produces light/heat
b)
production of a gas
c)
formation of a precipitate
d)
melting
27.
How do you balance a chemical equation?
a)
Add coefficients by trial/error
b)
Change subscripts
c)
Change superscripts
d)
You can't balance equations
28.
Write the balanced chemical equation for the following unbalanced equation: Fe + Cl2 → FeCl3
a)
Fe + Cl2 → FeCl3
b)
Fe + 3Cl2 → 2FeCl3
c)
2Fe + Cl2 → FeCl3
d)
2Fe 3Cl2 → 2FeCl3
29.
Is this balanced?...
Al + O2 --> 2Al2O3
Al + O2 --> 2Al2O3
a)
Yes!
b)
NO!
30.
Balance this equation...
Sb2S3 + O2 --> Sb + SO2
Sb2S3 + O2 --> Sb + SO2
a)
It is balanced
b)
Sb2S3 + 3O2 --> 2Sb + 3SO2
c)
Sb2S3 + O2 --> 2Sb + SO2
d)
I don't know...Oh well!
31.
Balance this equation-
__P4 + __O2 --> __P2O3
__P4 + __O2 --> __P2O3
a)
it is already balanced
b)
2, 1, 3
c)
1, 2, 3
d)
1, 3, 2
32.
Balance this equation
_N2 + _H2 --> _NH3
_N2 + _H2 --> _NH3
a)
1,2,3
b)
1,3,2
c)
1,1,2
d)
2,1,1
33.
Balance this equation.
_Mg + _Cl2 --> _MgCl2
_Mg + _Cl2 --> _MgCl2
a)
1, 2,1
b)
already balanced
c)
2,1,1
d)
1,1,2
34.
How many O's are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
35.
The substances at the beginning of a chemical equation are called the ____
a)
product
b)
yield
c)
chemical symbol
d)
reactants
36.
Number of H in 3(NH₄)₂CrO₄
a)
4
b)
2
c)
8
d)
24
37.
The red numbers in the image below represent ________
a)
subscripts
b)
coefficients
c)
I don't know, and don't want to try
d)
None of the answers are correct
38.
The blue numbers in the image below represent ________
a)
I don't know, and don't want to try
b)
coefficients
c)
subscripts
d)
none of the answers are correct
39.
In the equation, 2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
40.
In a chemical reaction, everything to the rightof the arrow is called ______________.
a)
Products
b)
Yields
c)
Molecules
d)
Reactants
41.
How many atoms of aluminum are on each side of the following equation: 4Al + 3O2 --> 2Al2 O3
a)
2
b)
6
c)
1
d)
4
42.
How many atoms of Hydrogen are in this compound
a)
1
b)
2
c)
3
d)
4
43.
In this compound structure of alcohol, how many Hydrogen atoms are there?
a)
2
b)
4
c)
6
d)
8
44.
A subscript is the small number below a(n) ________ that tells the number of _______ of that element.
a)
element symbol; atoms
b)
atom; element symbol
c)
subscript; protons
d)
compound; elements
45.
How many Oxygen are in H2O?
a)
1
b)
2
c)
0
d)
4
46.
How many Hydrogen are in 4H2O?
a)
6
b)
8
c)
2
d)
4
47.
How many Oxygen atoms are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
48.
Number of H in 3(NH₄)₂CrO₄
a)
4
b)
2
c)
8
d)
24
49.
A pure substance that cannot be broken down into simpler substances.
a)
element
b)
compound
c)
molecule
d)
carbon dioxide
50.
How many Magnesium are in 10MgCl2?
a)
10
b)
5
c)
20
51.
A subscript is the small number below a(n) ________ that tells the number of _______ of that element.
a)
element symbol; atoms
b)
atom; element symbol
c)
subscript; protons
d)
compound; elements
52.
If there is no subscript, there is ______ atom(s) of that element.
a)
0
b)
2
c)
only 1
d)
1 million
53.
What is the number of protons that the element in this image contain?
a)
14
b)
7
c)
15
d)
18
54.
How many Sodium (Na) are in 6NaCl?
a)
1
b)
12
c)
6
55.
Which of the following is a compound?
a)
Co
b)
O2
c)
C
d)
CO2
56.
Which is the correct formula for:
three hydrogen (H)
one sulfur (S)
four oxygen (O)
three hydrogen (H)
one sulfur (S)
four oxygen (O)
a)
H3SO4
b)
HSO4
c)
H4S3O
d)
H2O
57.
2H2 + O2 --------> 2H2O What are the reactants?
a)
----->
b)
2H2O
c)
2H2 +O2
58.
2H2 + O2 --------> 2H2O What is the yield?
a)
2H2O
b)
------>
c)
2H2 + O2
59.
2H2 + O2 ----> 2H2O What is the product?
a)
------>
b)
2H2O
c)
2H2+ O2
60.
What will weigh more when a chemical change is complete? The reactants before the chemical reaction, or the product after the reaction is complete?
a)
They both will weigh the same
b)
The product always weighs more than the reactant
c)
The reactant will weigh more than the product
d)
They both will loose mass after the reaction
61.
What is the Law of Conservation of mass?
a)
Mass is created in a chemical reaction
b)
Mass is created in a physical change
c)
New chemicals formed from a chemical reaction have a larger overall mass than the original reactants
d)
Mass is never created or destroyed
62.
Since gasses weigh nothing, when they are produced in a reaction they do not have to be accounted for.
a)
True
b)
False
63.
The number to the lower side of an element is a
a)
Subscript
b)
Superscript
c)
Coefficient
d)
Charge
64.
If reaction starts with 20g of reactants it should produce
a)
a total of 40g of products
b)
a total of 10g of products
c)
a total of 80 g of products
d)
a total of 20g of products
65.
Which are the reactants in the following reaction?
2Mg + O2 ---> 2MgO
2Mg + O2 ---> 2MgO
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
66.
A chemical reaction is balanced when
a)
both sides have the same elements
b)
Both sides have the same number of atoms
c)
Same subscripts
d)
Same coefficients
67.
Matter can not be created nor destroyed: it can only be
a)
Destroyed a little bit
b)
Invisible
c)
Transformed, changed
d)
None of the above
68.
Which is Chemical Equation is Balanced?
a)
CH₄+O₂------CO₂+2H₂O
b)
H₂+O₂-----2H₂O₄
c)
4Al+3O₂-----2Al₂O₃
69.
Which problem is balanced?
a)
PbO2 + 2H2
b)
SO2 + H20 --> H2SO4
c)
2Na + 2H2O --> 2NaOH + H2
70.
How many nitrogen atoms does NH3 have?
a)
1
b)
2
c)
3
d)
4
71.
Is this equation balanced or unbalanced?
2Fe2O3 + 3C --> 4Fe + 3 CO2
2Fe2O3 + 3C --> 4Fe + 3 CO2
a)
balanced
b)
unbalanced
72.
How many oxygen atoms are in this chemical formula?
a)
6 oxygen atoms
b)
2 oxygen atoms
c)
3 oxygen atoms
d)
4 oxygen atoms
73.
Is this balanced?
2HgO → 2Hg + O2
2HgO → 2Hg + O2
a)
Yes
b)
No
74.
Is this balanced?
Al + O2 → 2Al2O3
Al + O2 → 2Al2O3
a)
Yes
b)
No
75.
Which Chemical Equation is Balanced?
a)
CH₄+O₂------CO₂+2H₂O
b)
H₂+O₂-----2H₂O₄
c)
4Al+3O₂-----2Al₂O₃
76.
3Na4
What is the subscript?
What is the subscript?
a)
1
b)
2
c)
3
d)
4
77.
How many elements does PbNO3 have?
a)
2
b)
3
c)
4
d)
5
78.
How many nitrogen atoms does NH3 have?
a)
1
b)
2
c)
3
d)
4
79.
How many O's are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
100 %
