exam 1 questions

Question 1

liquids have __ shape and are mostly __?

Answer 1

indefinite, incompressible

Question 2

what is the mass (in grams) of 14.0mL of a liquid with a density of 1.34 g/cm^2?

Answer 2

18.8g.
14.0 ml times 1.34 g/cm^2 = 18.8g

Question 3

the correct result (indicating the proper number of significant figures) of the following calculation of the formula weight for calcium chloride, CaCl2 is…
40.078+ (2x35.45)

Answer 3

110.98

Question 4

which one of the following element names and symbols don’t match up correctly?

Answer 4

a. Pb, lead
b. Fe, iron
c. Ag, gold
d. K, potassium
e. Na, sodium

correct answer: C

Question 5

a liquid sample is a uniform throughout. distillation produces two liquids with different boiling points. the sample is?

Answer 5

homogenous mixture

Question 6

in the following list, only ___ is not an example of a chemical reaction.

Answer 6

a. combustion of propane
b. decomposition of water into hydrogen & oxygen
c. burning wood
d. mixing ethanol & water
e. the rusting of iron

correct answer: D

Question 7

potassium is a __ and sulfur is a __?

Answer 7

metal, nonmetal

Question 8

which is not a typical property of metal.

Answer 8

metals are good insulators against transfer of heat

Question 9

the empirical formula of a compound with molecules containing 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms is?

Answer 9

a. C12H24O12
b. C6H12O6
c. C3H9O3
d. C2H6O2
e. CH2O

correct answer: E

Question 10

in ionic compounds, atoms of __ only form ions with a -1 charge

Answer 10

a. alkaline earth metals
b. halogens
c. chalcogens
d. alkali metals
e. transition metals

Question 11

predict the empirical formula of the ionic compound formed between calcium and oxygen

Answer 11

a. CaO
b. CaO2
c. CaO
d. CuO
e. Ca2O2

correct answer: A

Question 12

sodium reacts with a certain nonmetal element to form a compound with the general formula Na2X. what would the most likely empirical formula be for the compound formed between magnesium and element X?

Answer 12

MgX

Question 13

the correct name for HCIO4 (aq) is?

Answer 13

a. hypochlorous acid
b. perchloric acid
c. hydrochloric acid
d. chloric acid
e. hydrogen chlorate

correct answer: B

Question 14

what is the correct name for the compound C5H12

Answer 14

a. propane
b. pentane
c. pentacarbon dodecahydride
d. carbon (V) hydride
e. hexane

correct answer: B

Question 15

a certain mass of carbon reacts with 64.0g of oxygen to form carbon monoxide. how many grams of oxygen would react with that same mass of carbon to form carbon dioxide?

Answer 15

128

Question 16

which pair of elements would you expect to exhibit the greatest similarity in their physical and chemical properties?

Answer 16

a. Li, Be
b. Sn, Sb
c. F, Fe
d. Ca, Mg
e. O,P

correct answer: d

Question 17

how many electrons does the Mg2+ ion possess

Answer 17

a. 12
b. 10
c. 14
d. 2
e. 18

correct answer: b

Question 18

there are __ electrons, __ protons and __ neutrons in an atom of 127 I

Answer 18

53,53,74

Question 19

when the following combustion reaction is balanced, the coefficients are
_C7H16 + _O2 -> _CO2 + _H2O

Answer 19

1,11,7,8

Question 20

how many atoms of hydrogen are in 32 g of CH4?

Answer 20

4.8*10**24

Question 21

which of the following contains the largest number of atoms (of any kind) in a mole of the substance?

Answer 21

a. S8
b. C6H14
c. Al2(So4)3
d. Na3PO4
e. Cl2

Question 22

there are _ mol of carbon atoms in 4 mol of C4H8O2

Answer 22

a. 4
b. 8
c. 16
d. 20
e. 32

correct answer: c

Question 23

what is the mass percent of carbon in carbonic acid (H2CO3)

Answer 23

a. 4.83%
b. 19.4%
c. 29.0%
d. 62.6%
e. 96.0%

Question 24

a compound that is composed of only carbon and hydrogen contains 75% C and 25% H by mass. what is the empirical formula of this compound?

Answer 24

a. CH2
b. C2H8
c. CH4
d. C3H
e. C4H8

correct answer: c

Question 25

which of the following is not one of the postulates of daltons atomic theory?

Answer 25

a. all matter is composed of tiny particles of atoms
b. atoms of one element are different from those of all other elements
c. during a chemical reaction, atoms are changed into atoms of different elements
d. compounds are formed when atoms of different elements combine
e. a given compound always has the same relative number and kinds of atoms

correct answer: c

Question 26

in a typical atom, the electrons make up about __ of the mass and __ of the volume

Answer 26

a. over 99.999%, less than 0.1%
b. 30%, 70%
c. 99%, 1%
d. less than 0.1%, over 99.999%
e. half, all

Question 27

which of the following are cations

Answer 27

a. copper in CuCL2
b. Mg2+
c. sodium in NaCl
d. HPO42-
e. all correct answers

answer: e

Question 28

which of the following masses is the largest?

Answer 28

a. 7.8*102 g
b. 0.78 g
c. 7.8*10-3 kg
d. 0.0078 Mg
e. 78000 mg

Question 29

gold and chlorine form an ionic compound whose empirical formula is AuCl3. the name of this compound

Answer 29

a. trichlorogold
b. gold (1) chloride
c. gold trichloride
d. gold (1) trichloride
e. gold (111) chloride

answer: e

Question 30

electrons and protons possess

Answer 30

a. the same charge and the same mass
b. opposite charges and different masses
c. opposite charges and same mass
d. same charge but different masses
e. different masses and no charge

Question 31

the combustion of propane (C3H8) produces carbon dioxide and water:
C3H8(g)+5O2(g)->3CO2(g)+4H20(g)
the reaction of 2.00 mol of C3H8 with 4.00 mol of O2 will produce __ mol of CO2

Answer 31

2.00

Question 32

under appropriate conditions, nitrogen & hydrogen undergo a combination reaction to yield ammonia:
N2(g)+3H2(g)-> 2NH3(g)
determine the mass of NH3 that can be formed if 28.0g of N2 reacts completely with excess hydrogen

Answer 32

34.0g

Question 33

under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield ammonia:
N2(g)+3H2(g)->2NH3(g)
if 28.0g of nitrogen gas reacts with excess hydrogen gas to produce an actual yield of 20.0g of ammonia, the percent yield of this reaction is?

Answer 33

59%