Download Chem 110, Exam. (1) Time : 90 min 2011 – 2nd term Model (D

Chem 110, Exam. (1)
Time : 90 min
2011 – 2nd term
Model (D)
Name:
Useful information
Number:
Avogadro ,s number (N A )  6.02 10 23
Section:
With the best wishes
General Chemistry Team work
Directions: for each of the following question, choose the letter that best answers the
question and place it on your answer sheet
[1] How many oxygen atoms are present in 196 g of H2SO4?
A. 0.393 atoms
B. 8 atoms
C. 3.945  1022 atoms
D. 4.816  1024 atoms
[2] Which of these elements is most likely to be a good conductor of electricity?
A. Ne
B. He
C. Cu
D. F
[3] When 40.0 g NH3 and 50.0 g O2 are mixed and react according to the equation
below, which is the limiting reagent?
4 NH3 +5O2  4NO + 6H2O
A.
B.
C.
D.
O2
NH3
NO
H2O
[4] The atomic masses of X (69.09 %) and X (30.91 %) are 62.9298 amu and 64.923
amu, respectively. Calculate the average atomic mass of X element.
A. 65.1147 amu
B. 64.4215 amu
C. 63.546 amu
D. 63.1239 amu
[5] How many moles of aluminum in 96.7 g of Al?
A. 0.279 mol
B. 3.58 mol
C. 7.43 mol
D. 4.21 mol
1
[6] Balance the equation with the smallest whole numbers?
___ HCl +___Ca(OH)2  ___ CaCl2 +___ H2O
A. 2, 1, 1, 2
B. 1, 1, 2, 2
C. 1, 2, 4, 1
D. 2, 2, 1, 3
[7] Atoms of the same element with different mass numbers are called:
A. isotopes
B. ions
C. neutrons
D. chemical formula
[8] How many protons, electrons and neutrons are found in a 119Sn4+ ion?
A. 50 p, 48e, 69n
B. 50 p, 46e, 69n
C. 50 p, 50e, 69n
D. 50 p, 69e, 50n
[9] Calculate the percent of nitrogen (N) in N2O5
A.
B.
C.
D.
30.4%
20.6%
25.9%
15.2%
[10] Express 6500 mm as decimeters.
A. 6.5 dm
B. 6.5  1012 dm
C. 65 dm
D. 6.5  106 dm
[11] How many grams of O3 in 2 mol of O3?
A.
B.
C.
D.
96 g
48 g
66 g
68 g
2
[12] Which of the following is the smallest distance?
A. 2.1 x 104 pm
B.
C.
D.
21 m
2.1 x 102 cm
21 mm
[13] The alkali metal elements are found in _______ of the periodic table.
A.
B.
C.
D.
Group 8A
Group 2A
Group 1A
Period 7
[14] Which of these equations are correct?
A. 0F = (0C – 1.8) 32
B. 0F = (0C – 32)/ 1.8
C. 0F = (1.8+ 32 + 0C
D. 0F =(1.8 x 0C) + 32
[15] Identify the ions and their charges Ca(OH)2.
A. Ca+, OHB. Ca+, OH2C. Ca2+, OHD. Ca2+, OH2[16] Which is the correct formula for nitrogen trichloride?
A.
B.
C.
D.
NCl3
NO3Cl2
N3Cl
NCl4
[17] When 0.077 mol of CaF2 are reacted with 0.081 mol of H2SO4 to form HF, the
actual yield of HF was 2.87 g. Calculate the percent yield of the reaction.
CaF2 + H2SO4
A.
B.
C.
D.
CaSO4+2HF
95.3%
93.3%
47.6%
62.5%
3
[18] Which pair of compounds has the same empirical formula?
A.
B.
C.
D.
C2H6O3 and CH2O
C6H6 and CH4
NO2 and N2O4
NO2 and N4O
[19] Determine the number of moles of C12H22O11 that present in 25.0 g of C12H22O11.
3.17 10-2 mol
7.30 10-2 mol
5.36 mol
4.25 mol
A.
B.
C.
D.
[20] Analysis of an unknown compound gave the following data (C) 44.4%, (H)
6.21%, (S) 39.5%, (O) 9.86%. The molar mass is 162 g/mol. What is the molecular
formula?
A. C6H10S2O
B. C4H15S5O2
C. C5H6S4O4
D. C2H7S3O4
Given the following densities at 25oC:
graphite: 1.8 g/cm3 iron: 7.9 g/cm3
[21]
A block of iron has a mass of 483 g. What is the mass of a block of graphite that has
the same volume as the block of iron?
A.
B.
C.
D.
483 g
2120 g
6870 g
110 g
[22] The SI prefixes giga and milli represent, respectively:
A. 10-9 and 10-6.
B. 106 and 10-3.
C. 103 and 10-3.
D. 109 and 10-3.
4
[23] What temperature is 200 K when converted to degrees Celsius?
A. 132 C
B. -73 C
C. 73 C
D. -23 C
[24] Which of these elements is metalloid?
A.
B.
C.
D.
Ca
Mg
Al
B
[25] Which of these is SI-derived unit for volume
A. ml
B. L
C. m3
D. cm3
[26] Mg2+ is an example of one of the following:
A. monatomic anion
B. monatomic cation
C. polyatomic cation
D. polyatomic anion
[27] The SI base unit of electrical current is
A. liter
B. candela
C. ampere
D. mole
[28] Which is the correct name for Mn2O7?
A. manganese (II) oxide.
B. magnesium heptoxide.
C. dimanganese heptoxide
D. manganese (VII) oxide.
5
[29] Which two of these ions have the same number of electrons?
-
A.
B.
-
and
and
2+
2+
C.
2+
and
2+
D.
2+
and
2+
[30] All the following statements are correct except:
A. A chemical equation uses chemical symbols to show what happens during
chemical reaction
B. Elements in the same group of the periodic table exhibit similar properties.
C. The molecular formula shows the number of atoms of each element in the
simplest ratio of substance.
D. Atomic mass is the mass of an atom in atomic mass units (amu).
6