Chemistry Midterm Review
Scientific Notation
8. Express each of the following numbers in standard scientific notation.
a. 0.04731
4.731 x 10 -2
b. 4284
4.284 x 10 3
c.4.201
4.201 x 10 0
d. 0.000000000141 1.41 x 10 -10
e. 52.3 5.23 x 10 1
f. 0.04909
4.909 x 10 -2
g. 54331000
5.4331 x 10 7
h. 0.981 9.810 x 10 -1
10. Express each of the following as “ordinary” decimal numbers.
a. 4.83 X 102 483
b. 7.221 X 10-4 .0007221
c. 6.1 X 100
6.1
d. 9.11X 10-8
.0000000911
e. 4.221 X 106 4221000
f. 1.22 X 10-3
0.00122
3
g. 9.999 X 10 9999
h. 1.016 X 10-5 0.00001016
i. 1.016 X 105 101600
Significant Figures
42. Round off each of the following numbers to three significant digits and write the
answers in standard scientific notation.
a. 312.4
312
3.12 x 10 2
b. 0.00031254 .000313
3.13 x 10 -4
c. 31,254,000
31,300,000 3.13 x 10 7
d. 0.31254
0.313
3.13 x 10 - 1
e. 31.254 X 10-3
.0313 x 10 0
3.13 x 10 – 2
54. Evaluate each of the following and write the answer to the appropriate number
of significant figures.
a. (4.031)(.08206)(373.1)/(.995)
3 sf 1.24 x 10 2
b. (12.011)/(6.002 X 10)
4 sf 2.001 x 10 -1
c. (.500)/(44.02)
3 sf 1.14 x 10 -2
d. (0.15)(280.62)
2 sf 4.2 x 10 1
Temperature Conversions
none on exam
this is a change !!!!!!!!!!!!
Terms for Matter:
1. Matter is anything that has ______mass______________________________ and occupies
space.
2. The three physical _____states__________________ of matter are solid, liquid, and gas.
3. Solids and liquids are virtually incompressible; they have
_____fixed____________________ volumes.
4. Liquids have definite volumes but are able to take on the shape of their
________container_______________.
5. In liquid substances, the molecules are very close to each other but are still able to
________move__________________ fairly freely.
6. Matter in the _____gas___________________ state has no shape and fills completely
whatever container holds it.
7. Discuss the similarities and differences between a liquid and a solid.
similar – have fixed volume diff – liquid can take shape of container
8. The ___greater________________ the forces among the particles in a sample of matter,
the more rigid the matter will be.
9. Consider three 10-g sample of water: one as ice, one as a liquid, and one as a
vapor. How do the volumes of each of these three samples compare with one
another? How is this difference in volume related to the physical state involved?
ice will take up more space than liquid, gas will be greater than both at same
pressure
particles in solids (except water) are closer together, less close in liquids, and far
apart in gases
10. In a sample of gaseous substance, more than 99% of the overall volume of the
sample is empty space. How is this fact reflected in the properties of a liquid or
solid substance?
can not expand much to take up more space
Physical and Chemical Properties
18. Classify the following as a physical or chemical changes/properties.
a. Copper pan requires a blue-green coating (patina) after use. chem
b. Drain cleaner dissolves a hair clog in a bathroom drain. chem
c. Hydrogen peroxide fizzes when applied to a wound. chem.
d. Acids produced by bacteria in plaque causes teeth to decay. chem
e. Marble statues deteriorate when attacked by acid rain. chem
f. Grape juice ferments when yeast is added. chem.
g. Mothballs vaporize in a cedar closet. physical
h. Alcohol feels cool as it evaporates from the skin. physical
i. Your car battery will run down if you leave the lights on chemical
J. Soap lathers when you wash your hands physical
k. The sulfur in eggs will turn a silver spoon black. chemical
20. A pure sample of a(n) _____element_________________ contains only one kind of
atom.
22. Compounds can be broken down into ___elements________________ by chemical
changes
Chapter 4: Know the terms
Examples: isotope – same element, different mass #, # of neutrons
, law of constant composition – a particular pure substance ( water, eg) always has
the same ratio of atoms of each element ( water is always h2o)
ion, atom with a charge
cation, positive ion – atoms loses electrons
anion, negative ion – atom gains electrons
diatomic molecule - 2 atoms of same element together
3. In addition to his important work on the properties of gases, what other valuable
contributions did Robert Boyle make to the development of the study of chemistry?
need to experiment, defined an element as substance that cannot be broken down
further and still keep same properties
8. In some cases, the symbol of an element does not seem to bear any relationship to
the name we use for the elements. Generally, the symbol for an element is based on
its name in another language. Give the symbols and names for five examples of such
elements. wolfram W tungsten antimomy Sb stibium lead Pb plumbum silver
Ag argentium Au gold aurum iron Fe ferrum
16. What does the “law of constant composition” tell us? How did Dalton’s atomic
theory help to explain this law? Give examples.
– a particular pure substance ( water, eg) always has the same ratio of atoms of
each element ( water is always h2o)
Dalton’s ATOMIC THEORY said matter is made of atoms. The idea that a substance
has the same composition fits in with the idea that it is made of particles that
combine in fixed proportions.
20f. Draw the following: a substance such as Ca3(PO4)2, containing three atoms of
one type (red), tow atoms of a second type (blue), and eight atoms of a third type
(green) This just says there are 3 Ca atoms, 2 P, 8 O
21. Indicate whether each of the following statements is true or false. If a statement
is false, correct the statement so that it becomes true.
Hilighted terms are important to note:
a. In his cathode ray tube experiment, J.J. Thomson obtained a beam
particles (negative charge electrons) whose nature did not depend on which
metal was contained in the tube.
b. Thomson assumed that there must be a positively charged substance in
the atoms, since isolated atoms have no overall charge (and there were negatively
charged particles in there) .
c. In the plum pudding model of the atom, the atom was envisioned as a
sphere of positive charge in which negaitively charged electrons were randomly
distributed.
22. Indicate whether each of the following statements is true or false. If false,
correct the statement so that it becomes true.
a. Rutherford’s bombardment experiments with metal gold foil suggested
that the alpha particles (helium nuclei ) positively charged were being deflected
by coming near a large, positively charged atomic nucleus.
b. The proton and the electron have different masses but opposite electrical
charges.
c. Most atoms also contain neutrons, which are slightly heavier than protons
but carry no charge.
38. Write the atomic symbol for each of the atoms described below.
a. Z=25, A=55
Mn mass # 55 atomic # 25 30 protons
b. atomic number =12, number of neutrons =31 Mg mass # 43 atomic # 12
c. Z =27, A =60 Co mass #60 neutrons= 33
d. number of protons =26, number of neutrons 31 Fe mass # 57
e. the isotope of I with a mass number of 131
atomic # 53 neutrons 78
f. mass number =244, number of protons =94 Pu neutrons 150
40. How many protons and neutrons are contained in the nucleus of each of the
following atoms? In an uncharged atom of each element, how many electrons are
present?
A.)
60
Co
P+ 27
No 33
e- 27
S
P+ 16
No 17 e- 16
Be
P+ 4
27
B.)
33
16
c.)
10
4
d.)
40
No 6
e- 4
Ar
P+ 18
No 22
e- 22
18
e.)
23
Na
P+ 11
No 12 e- 11
Kr
P+ 36
No 48 e- 36
11
f.)
84
36
42. Complete the following table.
Name
Neutrons
Nitrogen
6
__________
___nitrogen__
________
lead
___Fe_____
________
___krypton
Atomic #
Mass #
___7_______
__13______
_7_______
__124______
7
symbol
14
__82___
206
31
26
57_______
__48______
36
__84__
________
84
Kr
36
Write the number and name (if any) of the group (family) to which each of the
following elements belongs.
a. krypton noble gas
b. bromine halogen
c. K alkali metals
d. Aluminum
e. Na alkali metal
f. Barium alkaline earth
g. Ne noble gas
h. Fluorine halogen
74. For each of the following ions, indicate the total number of protons and electrons
in the ion. For the positive ions in the list, predict the formula of the simplest
compound formed between each positive ion and the chloride ion Cl-. For the
negative ions in the list, predict the formula of the simplest compound formed
between each negative ion and sodium ion Na +
a. Fe 2+ 26 p+ 24 e- FeCl2
e. S 2- 16 p+ 18 e- Na2S
3+
b. Fe 26 p+ 23 e- FeCl3
f. P 3- 15 p+ 18 e- Na3P
c. Ba 2+ 56 p+ 54 e- BaCl2
g. Br - 35 p+ 36 e- NaBr
+
d. Cs 55 p+ 54 e- CsCl
h. O 2- 8 p+ 10 e- Na2O
76. For the following processes that show the formation of ions, fill in the number of
electrons that must be lost or gained to complete the process.
a. Sr --> Sr 2+ + ____2__________________ e –
b. Se + ____2____________ e- --> Se 2c. Fe --> Fe2 + + _____2___________ ed. P + ________3_______ e- --> P3e. Br + _______1________ e- --> Brf. Au --> Au3 + _____3_____________ e78. On the basis of its location on the periodic table, indicate what simple ion each of
the following elements is most likely to form.
a. Ra (Z = 88) 2+
d. Fr (Z = 87) 1+
b. Te (Z = 52) 2e. At (Z = 85) 1c. I (Z = 53) 1f. Rn (Z = 86) 0 noble gas
1. A compound containing only two elements is called a ______binary
_______________ compound.
2. What are the two major types of binary compounds?
____type I____________________ and ______type II _____________________
6. Although the formula of sodium chloride is written simple as NaCl, the compound
actually contains ____Na+____________ and ___CL - _______________ ions.
7. NOT ON THE EXAM For a metallic element that forms two stable cations, the
ending ______________ is sometimes used for the cation with a lower charge.
8. We indicate the charge of a metallic element that forms more than one cation by
adding a ____roman numeral __________ after the name of the cation.
10. Give the name of each of the following simple binary ionic compounds.
a. Na3N sodium nitride
e. SrO strontium oxide
b. K2O potassium oxide
f. Al2Se3 aluminum selenide
c. Mgcl2 magnesium chloride
g. CsBr cesium bromide
d. CaBr2 calcium bromide
h. AgF silver (I) fluoride
12. In which of the following pairs is the name incorrect?
a. silver oxide S20 incorrect
b. aluminum sulfide Al2S3
c. Trisodium nitride Na3N
incorrect
d. barium dichloride BaCl2 incorrect
e. Strontium hydride SrH2
14. Write the name of each of the following ionic substances, using the system that
includes a Roman numeral to specify the charge of the cation.
a. PbCl2 lead (II) chloride d
d. Hg20 mercury (I) oxide
b. Fe2O iron( I) oxide
e. Hg2S mercury (II) sulfide
c. SnI2 tin (II) iodide
f. CuI copper (I) iodide
18. Write the name for each of the following binary compounds of nonmetallic
elements.
a. GeH4
germanium tetrahydride
d. SeO2 selenium dioxide
b. N2Br4
dinitrogen tetrabromide
e. NH3 ammonia nitrogen trihydride
c. P2S5
diphosphorus pentasulfide
f. SiO2 silicon dioxide
20. Write the name for each of the following binary compounds, using the periodic
table to determine whether the compound is likely to be ionic (containing a metal
and a nonmetal) or nonionic (containing only nonmetals)
a. B2H6
diboron hexahydride
d. Ag2S
silver (I) sulfide
b. Ca3N2
calcium nitride
e. CuCl2 copper (II) chloride
c. CBr4 carbon tetrabromide
f. NO Nitrogen monoxide
27. Complete the following list by filling in the missing names or formulas of the
oxyanions of chlorine.
ClO4-
_____perchlorate__________________
____ClO - ___________________
ClO3-
hypochlorite
__chlorate_____________________
_____ClO2__________________
chlorite
30. Write the formula for each of the following nitrogen-containing polyatomic ions,
including the overall charge of the ion. (don’t memorize: provided on midterm)
a. nitrate NO3 c. ammonium NH4 +
b. nitrite NO2-
d. cyanide CN-
36. Name each of the following compounds, which contains polyatomic ions.
a. NH4NO3 ammonium nitrate
d. Ca3(PO4)2 calcium phosphate
b. KClO3 potassium chlorate
e. NaClO4 sodium perchlorate
c. Cr(CN)3 chromium (II) cyanide
f. (NH4)2SO3 ammonium sulfite
40. Name each of the following acids.
NOT ON THE EXAM
a. HOBr
e. H2SeO4
b. HIO4
f. HOI
c. H3PO3
g. HIO2
d. HClO2
h. H2Te
42. Write the formula for each of these ionic substances. .
a. plumbic oxide
NOT ON THE EXAM
b. stannous bromide
c. cupric sulfide
d. cuprous iodide
e. mercurous chloride
f. chromic fluoride
44. Write the formula for each of the following binary compounds of nonmetallic
elements.
a. carbon dioxide CO2
b. sulfur dioxide SO2
c. dinitrogen tetrachloride N2Cl4
d. carbon tetraiodide C I 4
e. phosphorus pentafluoride P Fl5
f. diphosphorus pentoxide P2O5
46. Write the formula for each of the following compounds that contain polyatomic
ions. Be sure to enclose the polyatomic ion in parentheses if more than one such ion
is needed.
a. calcium phosphate Ca3(PO4) 2
b. ammonium nitrate NH4 NO3
c. aluminum hydrogen sulfate AL (HSO4)3
d. barium sulfate Ba SO4
e. ferric nitrate.
NOT ON THE EXAM
f. copper (I) hydroxide Cu(OH)
48. Write the formula for each of the following acids. .
NOT ON THE EXAM
a. hydrocyanic acid
e. hypochlorous acid
b. nitric acid
f. hydrofluoric acid
c. sulfuric acid
g. bromous acid
d. phosphoric acid
h. hyrdrofluoric acid
50. Write the formula for each of the following substances.
a. sodium hydrogen phosphate
b. magnesium acetate Mg (C2H3O2)2
c. strontium iodide
d. hydroselenic acid.
e. calcium phosphide
Sr I 2
NOT ON THE EXAM
Ca3P2
f. silver (I) perchlorate (usually called silver perchlorate)
g. iron (III) hydroxide
h. stannous fluoride.
Fe(OH)3
NOT ON THE EXAM
i. plumbous oxide.
NOT ON THE EXAM
j. diboron trioxide
B2O3
k. sodium dihydrogen phosphate
l. phosphorous acid.
Na H2PO4
NOT ON THE EXAM
2. A solution of hydrogen peroxide, H2O2, is often used to clean cuts and scrapes,
particularly if it is feared that anerobic bacteria such as clostridium (the microbe
that causes tetanus) have been introduced into the wound. What evidence is
there for chemical reaction taking place when hydrogen peroxide is applied to a
wound?
formation of a gas
4. Oven cleaners typically contain lye (sodium hydroxide), which converts the
greases and oils oiling the oven walls into soap, which can then be washed away
more easily. What evidence is there that such oven cleaners work by a chemical
reaction? new substances formed – heat generated
6. When fruit juice is left exposed to the air, it eventually ferments into wine or
vinegar. What evidence is there that a chemical reaction is occurring? bubbles,
smells different, looks much different
7. The substances present before a chemical reaction takes place are called the
_____reactants_________________, and the substances present after the reaction takes
place are called the ____products________________________.
8. In an ordinary chemical reaction, ____atoms (mass) ______________ are neither
created nor destroyed.
IN A NUCLEAR REACTION, MASS IS TURNED INTO ENERGY, SO IS “DESTROYED”
MASS IS NOT CONSERVED IN NUCLEAR REACTIONS
12. In a chemical equation for a reaction, the notation “(aq)” after a substance’s
formula means that the substance is dissolved in ____aqueous – dissolved in
water __________________
38. Balance each of the following chemical equations. (remember only put a
number in front of the reactants and products: as demonstrated in letter A)
a. _____Br2(l) +__2___ KI(aq) -->___2__ KBr(aq) +____ I2(s)
b. ___4__Co(s) +___3__ O2(g) -->__2___Co2O3(s)
c. _____P4(s) + ___5__O2(g) -->_____ P4O10(s)
d. __2___Al(s) + ___6__HNO3(aq) --> _2____Al(NO3)3 (aq) + __3___H2(g)
e. __1___PBr3(l) +___3__ H2O (l) --> __1___H3PO3(aq) +___3__HBr(aq)
f. __2___ NO (g) + _____ O2(g) --> ___2__ NO2 (g)
g. ___2__ C2H6(g) + ___7__ O2(g) --> ___4__ CO2(g) + __6___ H2O (g)
h. ___1__ CuO (s) + __1___ H2SO4(aq) --> CuSO4(aq) + H2O(l)
42. Balance each of the following chemical equations. (remember only put a
number in front of the reactants and products)
a. _____ SiI4(s) + __2___ Mg(s) --> _____ Si(s) + __2___ MgI2(s)
b. _____ MnO2(s) + __2___ Mg(s) --> _____ Mn(s) + __2___ MgO(s)
c. ___8__ Ba(s) + _____ S8(s) --> __8___ BaS(s)
d. ___4__ NH3(g) + __3___ Cl2(g) --> ___3__ NH4Cl(s) + _____ NCl3(g)
e. ___8__ Cu2S(s) + _____ S8(s) --> __16___CuS(s)
f. ___2__ Al(s) + ___3__ H2SO4(aq) --> _____ Al2(SO4)3(aq) + _3____ H2(g)
g. __2___NaCl(s) + _____ H2SO4 (aq) --> __2___ HCl(g) + _____ Na2SO4(s)
h.___2__ CO(g) + _____ O2(g) --> 2 CO2(g)