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MIDTERM REVIEW
Please get out: Paper, pencil,
calculator and all chemistry
knowledge 
Would freezing liquid
mercury be considered a
physical or chemical
change?
physical
Would dissolving sodium
chloride in water be
considered a physical or
chemical change?
physical
What are the two categories
of pure substances?
Elements and
compounds
How can an element be
further separated? By
ordinary physical means; By
ordinary chemical means; Or
it cannot be further separated
by ordinary physical or
chemical means.
Cannot be separated
by ordinary physical or
chemical means
As what type of matter
would you classify vinegar
(acetic acid in water)?
Homogeneous
mixture
At one point in the school
year, our room was a
comfortable 85°F. Is this
observation qualitative or
quantitative?
quantitative
A group of measurements
that closely agree with one
another but are far from the
“true” value are said to be…
precise
How many sig figs are in the
following measurement:
0.0390060
6 sf
Object A has a mass of 15.2 g
and a volume of 3.6 mL.
Object B has a volume of 4.1
mL and a mass of 16.8 g.
Which will sink first in
water?
Object A
(4.22g/mL vs.
B= 4.10g/mL
You are in the lab and need to
mix hydrochloric acid and
water. In what order should
you do this?
Pour acid into
water
Which subatomic particle
has a mass so small that it
is considered negligible
when finding mass
number?
electron
An unknown element has 38
protons, 36 electrons, and 50
neutrons. Identify the
element.
Always use protons
for identity
2+
Strontium (*Sr )
Isotopes occur when atoms of
the same element have
different mass numbers.
Therefore, an isotope has the
same # of ______, but a
different # of ______.
Same = protons
Different = neutrons
An atom has an atomic # of 31
and a mass # of 70. How
many protons, electrons, and
neutrons does the atom have?
Protons = 31
Electrons = 31
Neutrons = 39
What family has an
electron configuration
5
that ends in p ?
Halogens
What is the Noble
Gas configuration
for Selenium (Se)?
2
10
4
[Ar]4s 3d 4p
How many electrons can be
held in each energy level
(n=1-4) of the atom?
n = 1  2e- (s)
n = 2  8e- (s, p)
n = 3  18e- (s, p, d)
n = 4  32e- (s, p, d, f)
Do metals
generally form
cations or anions?
cations
Give the group and period
trend for atomic radius.
Decreases across a period,
increases down a column.
What type of elements tend to
form covalent/molecular bonds?
2 nonmetals
According to VSEPR theory,
what is the molecular geometry
of the compound silicon
tetrachloride?
Tetrahedral
What type of bond is likely to
form between two atoms with the
same electronegativity value?
A nonpolar covalent bond
When comparing single, double
and triple covalent bonds, a
single covalent bond has the
(shortest/longest) bond length
and the (strongest/weakest) bond
strength.
Single Covalent Bond
Longest – bond length
weakest – bond strength
What is the correct name for
Mn(C2H3O2)4?
Manganese (IV) acetate
What is the correct name for
C3H8?
Tricarbon octahydride
What is the correct formula for
ammonium sulfite?
(NH4)2SO3
A compound contains 47.0% K,
14.5% C, and 38.5 % O. Its
molecular weight is 166.22
g/mol. What is its molecular
formula?
K2C2O4
If aqueous solutions of strontium
chloride and sodium sulfate are
mixed together, will a precipitate
form?
Yes, strontium sulfate is
insoluble (s)
What do we call the ions that
appear in identical forms among
both the reactants and products of
a complete ionic equation that are
not written in the net ionic
equation?
Spectator ions
Classify and balance the reaction
below:
__ K3PO4 + __CdCl2  __KCl + __Cd3(PO4)2
Double Replacement
2 K3PO4 + 3 CdCl2  6 KCl + 1 Cd3(PO4)2
In the balanced combustion
reaction of ethane (C2H6), oxygen
has the stoichiometric coefficient
of ____.
Seven
2 C2H6 + 7 O2  4 CO2 + 3 H2O
What is the molar mass of
magnesium nitrate?
Mg(NO3)2 = 148.33 g/mol
How many moles of pyridine
(C5H5N) are contained in 3.13g
of pyridine?
0.0396 moles
In an experiment, a 0.33 mole
sample of N2 reacts completely.
What is the mass of Mg
consumed in the reaction?
3 Mg + N2  Mg3N2
24.07 g Mg
In an experiment, the reaction of
4.73g of Mg with 1.83g of H2O
actually produced 0.095g of H2.
What is the percent yield of this
reaction?
Mg (s) + 2 H2O (l)  Mg(OH)2 (s) + H2 (g)
92.23% yield