Chemical Compounds Practice Problems
1) What is the molecular, empirical, structural, condensed structural formula and the line angle drawings
of each of the following molecules:
1)
A) methane
B) ethane
C) ethyne
D) propene
E) methanol
F) ethanol
G) butanal
2) What is the empirical formula for fumaric acid, C4 H4 O4?
3) Which of the following molecular formulas is also an empirical formula?
A) C10H14N2 (nicotine)
B) C9 H8O4 (aspirin)
C) C6 H8O6 (vitamin c)
D) C8 H10N4 O2 (caffeine)
3)
4) The molecular formula of caffeine is C8 H10N4O2 . What is the percentage of each element by mass in this molecule?
5) What is the percentage of H2 O by mass in magnesium chloride hexahydrate?
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6) A sample contains 43.7% phosphorus and 56.3% oxygen by mass. What is its empirical formula? Can you determine
its molecular formula?
7) Using a mass spectrometer the compound from the previous question was found to have a mass of 283.89 amu. What
is the molecular formula of the compound?
8) A compound was found to be comprised of 36.763% iron, 21.108% sulfur and 42.128% oxygen by mass. What is its
empirical formula?
9) White phosphorus (P4), spontaneously ignites in oxygen. If 6.500 g of white phosphorus reacts with oxygen to form
11.54 g of a phosphorus oxide, what is the empirical formula of this oxide?
10) A sample of pure copper weighing 3.178 gram is burned in the pressence of oxygen until it is all
converted to a black oxide. The resultant black powder weighs 3.978 g. What is the formula of the oxide?
Is this the empirical formula or the molecular formula?
A) CuO2
B) Cu2O
C) CuO3
D) CuO
E) Cu2O3
10)
11) Complete combustion of a 0.500 g sample of a pure hydrocarbon yielded 0.973 g CO2 and 0.319 g H2 O. What is the
empirical formula of this hydrocarbon?
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12) A 4.055 g sample of a compound containing only C, H, and O was burned completely. The only combustion products
were 10.942 g CO2 and 4.476 g H2 O. What is the empirical formula of the compound?
13) An unknown compound has a formula of MCl3 where M is a metal ion. 2.395 grams of this compound contain
0.03606 moles of chlorine. Determine the identity of the metal.
14) Chlorophyll contains 2.72% magnesium by mass. If there is only one magnesium per chlorophyll molecule, what is
the molar mass of the chlorophyll molecule?
15) Anhydrous sodium sulfate is converted to the decahydrate when exposed to water vapor. If a 24.05 g sample of the
anhydrous compound is exposed to water vapor, how much would its mass increase?
16) Which of the following compounds contain an ion with a 3+ charge (may be more than one)?
A) Cu3(PO4)2
B) K2 SO4
C) FeCl3
D) Na2O
E) CoCl3
16)
17) Which of the following polyatomic ions has a 3- charge?
A) nitrate
B) dichromate
C) perchlorate
17)
18) What is the formula of the nitride ion?
A) NO33B) NO2-
C) NO32-
3
D) sulfate
D) N3-
E) phosphate
E) NO2-
18)
19) The name of the HSO4 - ion is __________.
19)
20) What is the formula of the ionic compound that forms between calcium and phosphate ions?
A) Ca3PO4
B) CaPO4
C) Ca3(PO4 )2
D) Ca2PO3
E) Ca3(PO3 )2
20)
A) bisulfite
B) hydrogen sulfite
C) hydrosulfate
D) hydrogen sulfate or bisulfate
E) aych-ess-o-four, three minus
21) What is the correct formula for the oxide ion?
21)
22) What is the correct name for Fe2 (SO4 )3?
22)
23) What is the formula for aluminum nitrite?
23)
24) What is the correct formula for copper(II) chloride?
24)
25) What is the correct formula for the ionic compound formed between cupric and sulfate ions?
25)
26) What is the correct name for FeS?
26)
27) What is the correct name for SnCl2?
27)
28) Ammonium carbonate has what formula?
28)
29) Ammonium hydrogen phosphate has what formula?
29)
30) What is the correct formula for the ionic compound formed between calcium and sulfate ions?
30)
31) Calcium bicarbonate has what formula?
31)
32) Vanadium(V) oxide has what formula?
32)
33) potassium dihydrogenphosphate has what formula?
33)
34) Iron(III) sulfite has what formula?
34)
35) Lead(II) iodide has what formula?
35)
36) What is the correct name for CaSO4 ?
36)
37) What is the correct name for FePO4 ?
37)
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38) Potassium phosphide has what formula?
38)
39) What is the correct formula for dinitrogen trioxide?
39)
40) What is the correct formula for sulfur dichloride?
40)
41) What is the correct name for CS2 ?
41)
42) What is the correct name for HCl(g)?
42)
43) What is the correct name for HCl(aq)?
43)
44) What is the correct name for HMnO4(aq)?
44)
45) What is the correct name for HClO3(aq)?
45)
46) What is the correct name for HClO(aq)?
46)
47) How many atoms of potassium are in 1.56 g of potassium dichromate?
48) How many micrograms of chromium are found in 65.456 mg of chromium(III) perchlorate hexahydrate?
49) How many hydrogen atoms are there in 12.4 g of aluminum hydrogen phosphate?
50) What mass (in mg) of 3-chloro-2-pentanol will yield exactly 1 mmol of this compound?
51) How many micrograms of cupric phosphate will provide 354.6 picomoles of copper?
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52) How many milliliters of ethanol are needed to provide exactly 100 millimoles of oxygen? The density of ethanol is
0.789 g/mL
53) In a 1.987 mg sample of zinc nitride there are how many nitrogen atoms?
54) How many µmols of nitrogen are in a 0.09734 mg sample of lanthanum(III) nitrate?
55) What is the name of the alkyl group CH3 - CH2- CH2 -?
A) isopropyl
B) propane
C) ethane
55)
D) ethyl
56) The functional group contained in the compound CH3 CH2 COOH is a(n) __________.
A) alcohol
B) carboxylic acid
C) aldehyde
D) ketone
E) ketohol
57) Draw the structure of 2,2,3,4-tetramethyl-1-pentanol.
58) Draw the structure of 2,4-dimethyl-5-propyldecanoic acid.
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E) propyl
56)
59) Name each of the following compounds:
59)
A) CH3- CH2 - CH2 - CH2- CH2 - CH2 - CH3
B) CH3 -CH2 -CH=CH-CH3
C) CH3CHO
D)
_________________________________
_________________________________
__________________________________
CH3
CH3- C -CH3
__________________________________
OH
E)
OH
CH3-CH2 -C- CH3
__________________________________
C H3
F) CH3 - CH -CHO
C H3
__________________________________
G) CH3 - CH-CH2 -OH
C H3
H)
O
CH3 C CHCH3
J)
__________________________________
__________________________________
Cl
__________________________________
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60) What is the correct name for the following organic structures.
CH3
A)
CH3
|
C
CH3
B)
CH2
CH3
CH3
CH3
60)
C
CH2
C H3
CH
CH3
|
C H2
CH3
C)
CH3
|
CH2 CHCH2 CHCH3
D)
Br Cl
| |
CH3CH2 CHCHCH3
E)
OH
|
CH3CH2 CH2CHCH2CH3
F)
Cl
|
CH3CH2 CH2CHCH2CH2CH2COOH
G)
CH3
|
CH2 CHCHC(CH3 )3
H)
J) CH CCH2 CHCH2 CH3
|
CH3
K)
L)
CH2CH3
|
CH2 CHCHCHCH2CH3
|
CH2 CH3
CH2CH3
|
CH2CH2 CHCH2 CHCH3
|
CH2 CH3
OH
M)
|
CH2CH2 CHCH2 CHCH3
|
CH2 CH3
CH2CHO
|
CH2CH2 CHCH2 CHCH3
|
CH2 CH3
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61) Draw the following molecules:
a) 3-bromocyclohexanol
b) 4-isopropylnonane
c) 3-methylpentanal
d) 3-chlorocyclohexene
e) Benzene
f)Toluene
g) Phenol
h) 1,3-dichlorbenzene
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