WorksheetsKnowledge Check -- Chemical Formulas
Total questions: 24
Worksheet time: 20mins
Name
Class
Date
1.
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
2.
Element or compound?
O2
O2
a)
Element
b)
Compound
3.
How many elements are in C6H12O6?
a)
1
b)
2
c)
3
d)
4
4.
A way to show the number and type of elements (atoms) in a molecule or compound with a combination of symbols and numbers.
a)
Molecule
b)
Chemical formula
c)
Physical change
d)
Coefficient
5.
The small number that is written below the symbol and shows how many atoms of each element is present.
a)
Compound
b)
Molecule
c)
Coefficient
d)
Subscript
6.
The large number written in front of a chemical formula. It shows the number of molecules.
a)
Molecule
b)
Compound
c)
Coeffiecient
d)
Subscript
7.
Which of the following is a compound?
a)
Co
b)
O2
c)
C
d)
CO2
8.
Which of the following is NOT an element?
a)
H2O
b)
H2
c)
O2
d)
Au
9.
The substances at the beginning of a chemical equation are called the ____
a)
product
b)
yield
c)
chemical symbol
d)
reactants
10.
In the equation, 2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
11.
In a chemical reaction, everything to the rightof the arrow is called ______________.
a)
Products
b)
Yields
c)
Molecules
d)
Reactants
12.
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
13.
How many atoms are there TOTAL in:
H2SO4
H2SO4
a)
6
b)
5
c)
7
d)
3
14.
How many O's are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
15.
Number of H in 3(NH₄)₂CrO₄
a)
4
b)
2
c)
8
d)
24
16.
The arrow symbol used in a chemical equation
a)
Yield sign
b)
Subscript
c)
Coefficient
d)
Chemical formula
17.
The law of conservation of mass states that....
a)
Matter can be made
b)
Matter can be destroyed
c)
Matter can neither be made or destroyed
18.
Is this balanced?...
Al + O2 --> 2Al2O3
Al + O2 --> 2Al2O3
a)
Yes!
b)
NO!
19.
At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?
a)
the product is doubled
b)
the product is half the mass of the reactants
c)
the mass is the same
d)
the mass changes depending on the reaction
20.
Why is the following chemical equation not balanced?
H2 + O2 --> H2O
H2 + O2 --> H2O
a)
each side of the equation has a different number of oxygen atoms
b)
each side of the equation has a different number of hydrogen atoms
c)
each side has the same mass
21.
Balance this equation...
H2 + Cl2 --> HCl
H2 + Cl2 --> HCl
a)
It is balanced
b)
3H2 + Cl2 --> 6H2Cl
c)
H2 + Cl2 --> 2HCl
22.
True or False: When balancing chemical equations the subscripts can change.
a)
true
b)
false
23.
What is the total number of atoms present in 5Na3PO4
a)
5
b)
40
c)
55
d)
60
24.
What coefficient should be used to make the following equation balanced?
N2+O2--> _NO
N2+O2--> _NO
a)
1
b)
2
c)
3
d)
4
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