exam 1 questions Flashcards
liquids have __ shape and are mostly __?
indefinite, incompressible
what is the mass (in grams) of 14.0mL of a liquid with a density of 1.34 g/cm^2?
18.8g.
14.0 ml times 1.34 g/cm^2 = 18.8g
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)
110.98
which one of the following element names and symbols don’t match up correctly?
a. Pb, lead
b. Fe, iron
c. Ag, gold
d. K, potassium
e. Na, sodium
correct answer: C
a liquid sample is a uniform throughout. distillation produces two liquids with different boiling points. the sample is?
homogenous mixture
in the following list, only ___ is not an example of a chemical reaction.
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
potassium is a __ and sulfur is a __?
metal, nonmetal
which is not a typical property of metal.
metals are good insulators against transfer of heat
the empirical formula of a compound with molecules containing 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms is?
a. C12H24O12
b. C6H12O6
c. C3H9O3
d. C2H6O2
e. CH2O
correct answer: E
in ionic compounds, atoms of __ only form ions with a -1 charge
a. alkaline earth metals
b. halogens
c. chalcogens
d. alkali metals
e. transition metals
predict the empirical formula of the ionic compound formed between calcium and oxygen
a. CaO
b. CaO2
c. CaO
d. CuO
e. Ca2O2
correct answer: A
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?
MgX
the correct name for HCIO4 (aq) is?
a. hypochlorous acid
b. perchloric acid
c. hydrochloric acid
d. chloric acid
e. hydrogen chlorate
correct answer: B
what is the correct name for the compound C5H12
a. propane
b. pentane
c. pentacarbon dodecahydride
d. carbon (V) hydride
e. hexane
correct answer: B
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?
128
which pair of elements would you expect to exhibit the greatest similarity in their physical and chemical properties?
a. Li, Be
b. Sn, Sb
c. F, Fe
d. Ca, Mg
e. O,P
correct answer: d
how many electrons does the Mg2+ ion possess
a. 12
b. 10
c. 14
d. 2
e. 18
correct answer: b
there are __ electrons, __ protons and __ neutrons in an atom of 127 I
53,53,74
when the following combustion reaction is balanced, the coefficients are
_C7H16 + _O2 -> _CO2 + _H2O
1,11,7,8
how many atoms of hydrogen are in 32 g of CH4?
4.8*10**24
which of the following contains the largest number of atoms (of any kind) in a mole of the substance?
a. S8
b. C6H14
c. Al2(So4)3
d. Na3PO4
e. Cl2
there are _ mol of carbon atoms in 4 mol of C4H8O2
a. 4
b. 8
c. 16
d. 20
e. 32
correct answer: c
what is the mass percent of carbon in carbonic acid (H2CO3)
a. 4.83%
b. 19.4%
c. 29.0%
d. 62.6%
e. 96.0%
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?
a. CH2
b. C2H8
c. CH4
d. C3H
e. C4H8
correct answer: c
which of the following is not one of the postulates of daltons atomic theory?
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
in a typical atom, the electrons make up about __ of the mass and __ of the volume
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
which of the following are cations
a. copper in CuCL2
b. Mg2+
c. sodium in NaCl
d. HPO42-
e. all correct answers
answer: e
which of the following masses is the largest?
a. 7.8*102 g
b. 0.78 g
c. 7.8*10-3 kg
d. 0.0078 Mg
e. 78000 mg
gold and chlorine form an ionic compound whose empirical formula is AuCl3. the name of this compound
a. trichlorogold
b. gold (1) chloride
c. gold trichloride
d. gold (1) trichloride
e. gold (111) chloride
answer: e
electrons and protons possess
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
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
2.00
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
34.0g
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?
59%
