Transcript C. - Knights of The Periodic Table

Nomenclature
Chemical Formulas
Reactions
Which is an example of a
synthesis reaction?
A. HCl + KOH  KCl + H2O
B. Pb(NO3)2 + 2HBr  PbBr2 + 2HNO3
C. C + O2  CO2
D. Mg + H2SO4  MgSO4 + H2
A + B  AB
2
A. 1, 1, 1
B. 1, 1, 2
C. 2, 1, 2
D. 2, 2, 1
2
The coefficients of
the correctly
balanced equation
for the reaction
illustrated are —
Which of the following
equations is balanced?
What would be the product(s)
of this reaction?
3MgO + 2Al  3 Mg + Al2O3
A. 2Mg3Al2O2
B. Mg3Al2 + 3O2
C. 6Mg + Al3O2
D. 3Mg + Al2O3
Elements from which two groups
in the periodic table would most
likely combine with each other to
form an ionic compound?
A. 1 and 2
B. 16 and 17
C. 1 and 17
D. 17 and 18
The diagram is a potential energy curve
for a reaction. Which number represents
the effect of a catalyst on the reaction?
A. 1
B. 2
C. 3
D. 4
Which is the correct formula
for iron (III) sulfate?
A. Fe3(SO4)2
B. FeSO4
C. Fe2(SO4)3
D. Fe2(SO3)3
Remember the Roman
Numeral is the charge of
the Iron
*Fe’s oxidation number
Fe3+ SO42-
Which of these represents the
empirical formula and the
molecular formula, respectively,
for a given organic compound?
A. CH and C2H2
B. CH and CH4
C. CH2 and C2H2
D. CH3 and C3H12
Empirical formula is the
simplest whole number ratio
Molecular formula is a multiple
of the Empirical formula
The system that shows a
decrease in entropy (disorder)
is —
A.
B.
C.
D.
air escaping from a tire
snow melting
salt dissolving in water
water freezing
In chemical compounds,
covalent bonds form when —
A. the electronegativity difference between
two atoms is very large
B. electrons are completely transferred
between two metals
C. pairs of electrons are shared between two
nonmetal atoms
D. two nonmetal ions are attracted to each
other by opposite charges
Covalent bonds result from sharing electrons
Each beaker shown above
contains 2.2 grams of iron
and 1 liter of 3M H2SO4 at
STP. Which reaction will
go to completion first and
More surface area! why?
A. Beaker A because of increased surface area
B. Beaker B because of increased surface area
C. Beaker A because of a higher concentration level
D. Beaker B because of a higher concentration level
A catalyst is a substance used in
chemical reactions to —
A. provide a higher activation energy pathway
B. decrease collisions between reactant
molecules
C. increase the rate of the reaction
D. change the equilibrium to favor products
Catalysts speeds up a chemical reaction by lowering the
activation energy!
Which reaction type best
describes the reaction above?
A. Combination
B. Decomposition
C. Single replacement
D. Combustion
1
3
?3 AgNO3 + ?AlCl
1
3 → ?AgCl + ?Al(NO
3)3
Which of these sets of coefficients will
balance this equation?
A. 3, 3, 2, 1
B. 3, 1, 3, 1
C. 1, 6, 1, 9
D. 9, 3, 3, 3
The formula for lithium nitride
is —
A. LiN
B. Li3N
C. Li3N3
D. NLi3
Li+ N3-
This diagram of a
chemical reaction
shows that the
reaction is —
More energy in products  energy went into products
A. endothermic
B. exothermic
C. reversible
D. at equilibrium
Ni(C2H3O2)4
How many atoms are represented
in this formula?
1 + 4(2) + 4(3) + 4(2) = 29
A. 5
B. 8
C. 28
D. 29
The correct structural formula
for C2H4 is
Carbon forms 4 bonds!
Only 2 hydrogen
What type of reaction does this
illustration represent?
AB
A. Decomposition
B. Synthesis
C. Single-replacement
D. Double-replacement
A+B
Which of these reactions shows
simple chemical decomposition?
A compound has 50% sulfur and
50% oxygen. What is its
empirical formula?
Percent to mass
Mass to mole
Divide by small
Multiply to whole
A compound has 50% sulfur and
50% oxygen. What is its
empirical formula?
50 gS
1molS
x
 1.56molS / 1.56  1
32.1gS
50 gO 1molO
x
 3.13molO / 1.56  2
16 gO
A compound has 50% sulfur and
50% oxygen. What is its
empirical formula?
A.
B.
C.
D.
SO4
S2O4
SO3
SO2
The Lewis electron dot system
represents electrons in the —
A. outer energy level
B. inner level
C. middle level
D. core level
A(s) + B(s)  D(g) + heat
The reaction shown above is —
Heat is a product therefore the reaction is …
A. an endothermic reaction
B. an exothermic reaction
C. a decomposition reaction
D. a double-replacement reaction
The correct name for MgI2 is —
A. magnesium iodide
B. magnesium iodite
C. magnesium (II) iodide
D. magnesium diiodide
Mg2+  Magnesium Ion
I2 actually 2 I-  Iodide ion
If the diagram were the
correct representation for the
Lewis structure of a molecule,
then the X would be representative of the
element
—
A. oxygen
B. fluorine
C. nitrogen
D. sulfur
Exception
Chlorine and bromine are in the same family
in the periodic table. According to the
information in the table, what would be the
correct formula for sodium bromate?
A. NaBrO
B. Na2BrO
C. Na3BrO3
D. NaBrO3
Which of the groups
below has the electron
dot structure shown
above?
7 dots = 7 valance electrons
which is group 17
A . Noble gases
B. Halogens
C. Alkali metals
D. Transition elements
When naming a transition metal that
has more than one oxidation number,
the numeric value of the oxidation
number is indicated by a —
A. Roman numeral
B. Greek prefix
C. subscript
D. suffix
A compound is composed of
85.64% carbon and 14.36%
hydrogen. The compound has a
formula mass of 42.08 grams.
What is the molecular formula?
A. CH2
B. C3H6
C. C2H4
D. C2H18
Change % to mass to moles divide by small
85.64 gC 1 mol C = 7.137 / 7.137 = 1 C
12 g C
14.36 g H 1 mol H = 14.36 / 7.137 = 2 H
1gH
Calculate the mass of the empirical formula
CH2 1(12) + 2(1) = 14
Divide into molecular mass
42.08/14 = 3
Multiply by the empirical formula 3(CH2) = C3H6
Another way….
A. CH2 1(12) + 2(1) = 14 g
B. C3H6 3(12) + 6(1) = 42 g
C. C2H4 2(12) + 4(1) = 28 g
D. C2H18 2(12) + 18(1) = 42 g
The molar mass was 42 and there are two
answers that are 42 but C2H18 is a formula
that is not possible carbon only forms 4
bonds! Therefore B is the correct answer.
A compound is composed of
85.64% carbon and 14.36%
hydrogen. The compound has a
formula mass of 42.08 grams.
What is the molecular formula?
A. CH2
B. C3H6
C. C2H4
D. C2H18
Which of the following is the
correct molecular shape of CH4?
A. Bent
B. Linear
C. Pyramidal
D. Tetrahedral
According to the
table, which of
these probably
has the strongest
bonds?
Highest BP and MP!
A. Hydrogen gas
B. Iron crystals
C. Sodium chloride
D. Water
The empirical formula for
ethyne (C2H2) is —
Empirical formula = simplest formula
A. CH
B. C2H2
C. CH2
D. C2H
The type of reaction represented
by the above equation is —
A. single-replacement
B. double-replacement
C. synthesis
D. decomposition
2
3
2
3
When this equation is correctly
balanced, the coefficient of the AlCl3
will be —
A. 1
B. 2
C. 4
D. 6
A catalyst accelerates a chemical
reaction because the —
A. catalyst decreases the number of collisions in a
reaction
B. activation energy of the reaction is lowered in
the presence of a catalyst
C. catalyst decreases the concentration of the
reactants
D. temperature of the reaction increases due to the
catalyst
A compound is composed of 58.8%
C, 9.8% H, and 31.4% O, and the
molar mass is 102 g/mol. What is
the molecular formula for this
compound?
A. C2H10O 3
B. C5H5O3
C. C5H10O2
D. CH3O3
Find Empirical Formula
Change % to mass
Mass to Mole
Dividie by small
Multiply to whole
Find multiple of empirical
formula to molecular formula by
Mass
Or you can find the molar mass of
each formula in answer choices and
see which one equals 102…. C.
C5H10O2 5(12) + 10(1) + 2(160) =
102 g
A compound is composed of 58.8%
C, 9.8% H, and 31.4% O, and the
molar mass is 102 g/mol. What is
the molecular formula for this
compound?
A. C2H10O 3
B. C5H5O3
C. C5H10O2
D. CH3O3
Which of these completes this
reaction?
A. Oxygen
B. Hydrogen
C. Metal oxide
D. Air
Example:
2Na + 2HOH  2NaOH + H2
A balanced chemical equation has
equal numbers of atoms of each
type on both sides of the equation.
This illustrates the principle of —
A. conservation of energy
B. conservation of mass
C. action and reaction
D. natural selection
The type of bond found in magnesium
chloride is —
Magnesium group 2 (metal) Chlorine group 17 (nonmetal)
A. covalent
B. nonpolar
C. ionic
D. metallic
If the temperature of a reaction is
increased, the reaction proceeds at
a much quicker rate because the —
A. activation energy increases
B. energy of the products increases
C. frequency of collisions between reactants
increases
D. energy of the activated complex increases
In the above reaction, a cloudiness at
completion due to colloidal suspension of
sulfur appears. If the reaction is carried out
at various temperatures, at which
temperature would it proceed at the fastest
rate?
A. 20º C
B. 30º C
C. 40º C
Higher Temperature faster rate!
D. 50º C
The formula H2SO4 is representative
of which of the following?
A. A catalyst
B. A base
C. An acid
D. An organic compound
A heated liquid placed in a closed
container will vaporize until —
A. the boundary between liquid and vapor
disappears
B. all the liquid molecules become vapor
molecules
C. the number of liquid molecules vaporizing
equals the number of vapor molecules
condensing
D. the vapor pressure is greater than the
atmospheric pressure
Which compound contains
both ionic and covalent bonds?
A. NH4Cl
B. MgBr2
C. CH4
D. NH3
Polyatomic ions are held
together by covalent
bonds!
Which of the following containers of
water best shows dynamic equilibrium
between vapor and liquid?
Open jar
To indicate the number of atoms of
each element present in a
molecular compound, scientists
use —
A. Roman numerals
B. superscripts
C. prefixes
D. subscripts
CH4
Using the chart,
which of these
combinations will
probably form a
precipitate?
A. Ammonium chloride
B. Barium bromide
C. Calcium chromate
D. Copper (II) carbonate
The correct name for the compound
CCl4 is —
A. carbon tetrachloride
B. carbon chloride
C. monocarbon chloride
D. tetracarbon monochloride
Which of these is the general formula
for a double-replacement reaction?
A.
B.
C.
D.
A +B  AB
AB + XY  BA + YX
AB + XY  AY + XB
A + B + XY  AX + BY
The correct formula of an ionic
compound containing Al3+ and CO32- is
—
Al3+ CO 23
A.
B.
C.
D.
AlCO3
Al(CO3)3
Al2(CO3)3
Al3(CO3)2
Aluminum +Sulfuric Acid  Aluminum Sulfate
+ Hydrogen Gas
Which of the following is the balanced
chemical equation for the reaction
shown above?
Which answer is balanced?????
A. Al + H2SO4  Al2(SO4)3 + H2
B. 2Al + 3H2SO4  Al2(SO4)3 + 3H2
C. 2Al + 3H2SO4  Al2(SO4)3 + H2
D. 2Al + H2SO4  Al2(SO4)3 + H2
The figure shows a compound
containing hydrogen (H) and an
unknown element Z. To which
group on the periodic table does
element Z belong?
A. 13
B. 14
C. 15
D. 16
The element Z forms three bonds
which means it has 3 valance
electrons in addition to the pair
show. That gives it 5 valance
electrons. Which group has 5
valance electrons.
Which of the following is the name
of the molecule PCl3?
A. Phosphorus trichloride
B. Phosphorus chloride
C. Potassium trichloride
D. Potassium chloride
The appropriate model for a
decomposition reaction is —
The formula for dinitrogen
tetroxide is —
A. N2O4
B. N3O3
C. N2O2
D. NO
dinitrogen tetroxide
What is the correct Lewis dot
structure for arsenic?
Arsenic (As) is in group 15!
Which means 5 valance electrons
Or 5 dots!
The empirical formula for a substance is
CH2. If the molecular mass of the substance
is 56, the molecular formula is
A. C2H4
B. C3H6
C. C4H8
D. C5H10
Molar Mass
CH2 = 1(12) + 2(12) = 14
56/14 = 4
4(CH2) =
H2O(l)  H2O(g)
Water molecules in a sealed jar are in a
state of dynamic equilibrium because water
vapor molecules —
Equilibrium same rate condensing and evaporating
A. are condensing at the same rate that others are
evaporating
B. cease to form when the air in the jar becomes
saturated
C. are evaporating faster than they are condensing
D. form only at high temperatures
The diagram shows the
structural formula of
benzene. The empirical and
the molecular formulas of
benzene are, respectively —
A. CH, C2H2
B. CH, C3H3
C. C3H3, C6H6
D. CH, C6H6
6 Carbon atoms and 6 Hydrogen atoms
Divide by 6 gives you ……….
2Al
 AlCl
2AlCl
Al ++ 6HCl
HCl 
3 + H3H
3+
2 2
When the above equation is
balanced, the coefficient of the
hydrochloric acid will be
A. 2
B. 3
C. 4
D. 6
2NO(g) + O2(g)  2NO2(g) ΔH = - 27 kcal
Which graph represents the reaction
shown above?
ΔH = - 27 kcal Means the reaction was exothermic
releasing energy. Therefore the products have less
energy then the reactants
2NO(g) + O2(g)  2NO2(g) ΔH = - 27 kcal
Which graph represents the reaction
shown above?
Which Graph shows less energy in products than
reactants? ? ? ? ? ? ? ?
Which of the following occurs when a
reaction in a solution is at equilibrium
and more product is added to the
solution?
A. Equilibrium shifts to produce more product
B. Equilibrium shifts to produce more reactant
C. No change will occur
D. The reaction will stop
What shape does the molecule BF3 have?
A. Bent
B. Linear
C. Tetrahedral
D. Trigonal planar
Boron (B) is in group 13
therefore B has three valance
electrons.
Fluorine (F) is a Halogen and
therefore has 7 valance electrons
F and B Bond by 3 bonds
F
B
F
F
CaSO4 + Al(OH)3  Ca(OH)2 + Al2(SO4)3
3CaSO4 + 2Al(OH)3  3Ca(OH)2 + Al2(SO4)3
When the above equation is balanced, the
coefficients in order are —
A. 1, 1, 1, 1
B. 2, 1, 1, 2
C. 3, 1, 3, 2
D. 3, 2, 3, 1
The correct name for P2O5 is —
A. phosphorus (V) pentoxide
B. phosphorus oxide
C. phosphorus (II) oxide
D. diphosphorus pentoxide
Which set of coefficients will balance
this equation?
A. 1, 3, 1, 1
B. 2, 3, 2, 6
C. 2, 6, 2, 3
D. 3, 6, 3, 2
Al + HCl  AlCl3 + H2
2Al + 6HCl  2AlCl3 + 3H2
Using the table, what is the correct
formula for ammonium phosphate?
A. NH4PO4
B. (NH4)2(PO4)3
C. (NH4)3PO4
D. NH4(PO4)3
Which half-reaction represents
reduction?
A. Cu0 → Cu+2 + 2eB. Fe+2 → Fe+3 + 1eC. Ag+1 + 1e- → Ag0
D. Al0 → Al+3 + 3eRemember “LEO the lion goes GER”
LEO  Lose Electrons Oxidized
GER  Gain Electrons Reduced
Which of the following best represents
the reaction between hydrochloric acid
and sodium hydroxide?
A. 2HCl + 2NaOH → Na(OH)2 + H2Cl2
B. HCl2 + 2Na(OH)2 → 2H2O +2NaCl + OH
C. HCl + NaOH → H2O + NaCl
D. 2HCl + Na(OH)2 → 2H2 + NaCl + O2
The type of formula that shows the
arrangements of atoms and bonds is
called —
Structural = Arrangement
A. empirical
B. chemical
C. molecular
D. structural
What is the molecular formula of a
substance that has an empirical
formula of C2H5 and a molecular mass
of 58 g/mole?
A. C2H5
B. C5H2
C. C4H10
D. C6H15
Molar Mass C2H5 = 2(12) + 5(1) = 29g/mole
58/29 = 2
2(C2H5) = C4H10
Na2CO3 + Ca(OH)2  2NaOH + CaCO3
Which type of reaction is represented
here?
A. Single replacement
B. Double replacement
C. Synthesis
D. Decomposition
The empirical formula for C6H12 is —
A. C3H6
B. C2H4
C. CH3
D. CH2
2O3 (g)  3 ______ (g)
Which completes the chemical
equation above?
A. O2
B. O3
C. ClO
D. ClO2
Total of 6 Oxygen
An alien astronaut landed on Earth and
created the periodic table shown. The
astronaut was trying to determine what type
of bond would be present in several
compounds. The type of bond in a
compound containing G and E would be —
The type of bond in a compound containing
G and E would be —
A. a metallic bond
B. a nonmetallic bond
C. a covalent bond
D. an ionic bond
Calcium carbonate was
placed in a flask on a
balance, and dilute
hydrochloric acid was
added. Carbon dioxide
that was produced escaped
from the flask. The total
mass of the flask and its
contents was recorded
every 10 seconds. The
diagram above shows a
plot of the results. Between
which of the following
times was the reaction the
fastest?
Between which of the following times was the reaction the
fastest?
A. 0 and 10 seconds
B. 10 and 20 seconds
C. 20 and 30 seconds
D. 30 and 40 seconds
Bonding between two elements of
equal electronegativity would be —
A. 100% covalent
B. primarily ionic
C. 50% ionic
D. metallic in character
The molar mass (gram formula mass)
for the compound sodium thiosulfate,
Na2S2O3, is—
2(23) + 2(32.1) + 3(16) = 158.2
A. 71 grams
B. 153 grams
C. 158 grams
D. 254 grams
The correct formula for copper (I)
bromide is —
A. CuBr
B. CuBr2
C. Cu2Br
D. Cu2Br3
Cu+ Br-
Which of the
following models a
synthesis reaction?