WorksheetsChemistry Starters
Total questions: 21
Worksheet time: 24mins
Name
Class
Date
1.
What type of change is this?
a)
A chemical change
b)
A physical change
c)
A light change
d)
A light saber
2.
An ice cube melting and then refreezing would be a _____change.
a)
Physical
b)
Chemical
c)
Water
d)
Natural
3.
Physical properties are
a)
properties that can be observed without changing the identity of the substance
b)
properties that describe how a substance changes into a completely different substance
c)
properties that we can only observe with our eyes
d)
properties that we need special tools to observe
4.
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
5.
How many electrons does an atom with 8 protons have?
a)
8
b)
16
c)
15.99
d)
24
6.
A substance that is formed as the result of a chemical reaction
a)
Product
b)
Reactant
c)
Starters
d)
Enders
7.
the starting materials in a chemical reaction
a)
Products
b)
Reactants
c)
Starters
d)
Enders
8.
Why must we balance chemical equations?
a)
Our teacher said so
b)
to abide by the law of conservation of energy
c)
to abide by the law of conservation of mass
9.
Fill in the blank to balance the chemical equation.
2KI + ____Cl2 → 2KCl + I2
2KI + ____Cl2 → 2KCl + I2
a)
1
b)
2
c)
3
d)
4
10.
What is a coefficient?
a)
The small number on the right of the chemical symbol.
b)
The large number in front of a chemical formula.
c)
The number in between the chemical symbols.
d)
The number behind a chemical formula.
11.
What is the part of the chemical equation in green called?
Fe + S --> FeS
Fe + S --> FeS
a)
products
b)
reactants
c)
yield
d)
chemical formula
12.
How many HCl molecules do you need to balance this equation?
Mg + __HCl ---> MgCl2 + H2
Mg + __HCl ---> MgCl2 + H2
a)
1
b)
2
c)
3
d)
4
13.
A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen(N) by mass. What is the empirical formula?
a)
Mg4N3
b)
MgN2
c)
Mg3N2
d)
MgN
14.
Which of the following is considered an empirical formula?
a)
CH3COOH
b)
C6H12O6
c)
H2O
15.
You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements.
a)
SO
b)
SO2
c)
SO3
d)
SO4
16.
Which pair has the same empirical formula?
a)
NaCrO4 and Na2Cr2O7
b)
C2H4O2 and C6H12O6
c)
C3H6O3 and C2H6O2
d)
CH4 and C2H6
17.
A formula with the lowest whole # ratio of elements in a compound is called
a)
Molecular Formula
b)
Chemical Formula
c)
Empirical Formula
d)
Distance Formula
18.
Glycerol has a molar mass of 92.09g/mol. Its percent composition is: 39.12% C, 8.75% H, and 51.12% O. What is the molecular formula for glycerol?
a)
C2H3O2
b)
CH2O
c)
C2H4O2
d)
C3H8O3
19.
What is the empirical formula for C3H8
a)
CH
b)
C3H8
c)
C6H16
d)
CH2.7
20.
What is the molar mass of table salt (NaCl)?
a)
116.886 g/mol
b)
35.453 g/mol
c)
22.990 g/mol
d)
58.443 g/mol
21.
What is the empirical formula if you have 81.82% carbon and 18.18% hydrogen?
a)
C3H8
b)
CH4
c)
C2H2
d)
C4H10
100 %
