Download General Chemistry Team work Directions

Chem 110, First Exam
Time : 90 min
2011 - 2st term
Model (B)
Name:
Useful information:
N A  6.02  10 23 mol 1
Number:
Section:
With the best wishes
General Chemistry Team work
1
Directions: for each of the following question, choose the letter that best answers the
question and place it on your answer sheet
[1] The Nobel gases elements are found in ____ of the periodic table.
(A)
(B)
(C)
(D)
Group 8A *
Group 2A
7th period
Group 7A
[2] How many moles of nitrogen (N2) are present in 56 g of N2?
(A)
(B)
(C)
(D)
3 mol
5 mol
4 mol
2 mol *
[3] Identify the ions and their charges Na2CO3
(A) Na+, CO3+
(B) Na+, CO3(C) Na+, CO32+
(D) Na+, CO32- *
[4] Which is the correct formula for iron(II)phosphate?
(A)
(B)
(C)
(D)
Fe3PO4
Fe2PO4
Fe3(PO4)2 *
Fe(PO4)2
[5] Which of these quantities represents the largest mass?
(A)
(B)
(C)
(D)
500 mg
0.05 kg *
5103 µg
5g
2
[6] How many protons, electrons and neutrons are found in a 127Te2- ion?
(A)
(B)
(C)
(D)
50p, 48e, 69n.
52p, 50e, 75n.
52p, 54e, 75n *.
52p, 75e, 54n.
[7] How many oxygen atoms are present in 0.363 g of HClO4
(A)
(B)
(C)
(D)
1.261024 atoms
7.51022 atoms
8.71021 atoms*
8.71023 atoms
[8] Which of these equations is correct?
(A)
(B)
(C)
(D)
0
C= (0F + 32)/1.8
0C= (0F - 32)/1.8 *
0
C= (0F + 32) 1.8
0
C= (0F + 32-1.8)
[9] Which of these elements is most likely to be a good conductor of electricity?
(A)
(B)
(C)
(D)
He
Ni *
Cl
P
[10] Which of these is SI-derived unit for density?
(A)
(B)
(C)
(D)
Kg/m3 *
g/cm3
g/mL
Kg/cm3
[11] The atomic masses of X(75.53%) and X(24.47%) are 34.968 amu and 63.956 amu,
respectively. Calculate the average atomic mass of X element.
(A)
(B)
(C)
(D)
38.96 amu
38.47 amu
71.92 amu
35.45 amu *
3
[12] Which two of these ions have the same number or electrons?
(A)
127 
137
and
53
56
(B)
127 
119
and
53
50
(C)
119
50
(D)
I
I
Sn 2 
207
82
and
Pb2 
Ba 2  *
Sn 2 
137
56
and
Ba 2 
137
56
Ba 2 
[13] Given the following densities at 25ºC:
Magnesium: 1.7 g/cm3,
iron: 7.9 g/cm3
A block of iron has a mass of 826g. What is the mass of a block of magnesium that has
the same volume as the block of iron?
(A)
(B)
(C)
(D)
1400 g
3800 g
830 g
178 g *
[14] Balanced the following equation in the smallest whole numbers:
--- NaClO3 (s)
(A)
(B)
(C)
(D)
---NaCl (s) + --- O2 (g)
2,2,3 *
3,2,1
1,3,2
2,3,2
[15] What temperature is 77K when converted to ºC?
(A)
(B)
(C)
(D)
50 °C
-126 °C
67.8 °C
-196 °C *
4
[16] Calculate the percent of sulfur (S) in Al2(SO4)3
(A)
(B)
(C)
(D)
9.38 %
18.8 %
28.1 %*
24.6 %
[17] The SI base unit of luminous intensity is.....
(A)
(B)
(C)
(D)
liter
meter
Candela *
Mole
[18] How many grams of hydrogen (H) are there in 0.25 mol of C4H8?
(A)
(B)
(C)
(D)
4g
8g
1g
2g*
[19] What is the correct formula for sulfur dichloride ?
(A)
(B)
(C)
(D)
SCl2 *
S2Cl
SO3Cl
S2Cl2
[20] Atoms of the same element with different mass numbers called:
(A)
(B)
(C)
(D)
ions
isotopes *
neutrons
chemical formula
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[21] All the following statements are correct except:
(A) A chemical equation uses chemical symbols to show what happens during
chemical reaction.
(B) The molecular formula shows the number of atoms of each element in the
simplest ratio of substance *.
(C) The mass number indicates the total number of neutrons and protons in a
nucleus.
(D) Elements in the same group of the periodic table exhibit similar properties.
[22] Which of these elements is metalloid?
(A) Ge *
(B) Br
(C) Al
(D) Ba
[23] Analysis of an unknown compound gave the following data (C) 55.8%, (H) 7%, (O) 37.2%.
The molar mass is 86 g/mol. What is the molecular formula?
(A)
(B)
(C)
(D)
C2H3O2
C4H6O2*
C3H6O2
C2H4O
[24] When 23g NaCl and 21g H2SO4 are mixed and reacted according to the equation below,
which is the limiting reagent?
2NaCl + H2SO4
(A)
(B)
(C)
(D)
Na2SO4 + 2HCl
H2SO4
NaCl *
Na2SO4
HCl
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[25] When 6 mol of NH3 are reacted with 2 mol of CO2 to form urea CO(NH2)2, the actual
yield of urea was 95.5 g. Calculate the percent yield of the reaction.
(A)
(B)
(C)
(D)
79.6% *
81.3%
89.6%
75.1%
[26] Express 1x10-8 cm as nanometers.
(A)
1x10-19 nm
(B)
1x101 nm
(C)
1x10-10 nm
(D)
1x10-1 nm *
-----------------------------------------------------------------------------------------------[27] The SI prefixes kilo and mili represented respectively:
(A)
(B)
(C)
(D)
10-9 and 10-6
106 and 10-3
103 and 10-3 *
109 and 10-6
[28] Which of the following molecule is a diatomic molecule?
(A)
(B)
(C)
(D)
N2O
N2O4
NO2
NO*
[29] Which pair of compounds has the same empirical formula?
(A)
(B)
(C)
(D)
C2H6O3 and CH2O
C6H6 and CH4
NO2 and N4O
NO2 and N2O4 *
[30] What is the mass in grams of one atom of iron?
(A)
(B)
(C)
(D)
9.28  10-23 g *
6.02  1023 g
1.66  10-24 g
5.81  10-23 g
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