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Multiple Choice
1.
The weight of sulfur required to make 1.00 metric ton (1000 kg) of H2SO4 is:
A) 100 kg
C) 327 kg
2.
Find the empirical formula of a compound containing 52.9% carbon and the rest
oxygen.
A) C2O2
C) C5O2
3.
B) 2
D) 4
A gas has a density of 1.96 g/L at STP. What is its density at 650 torr and 25oC.
A) 2.53 g/L
C) 1.25 g/L
8.
B) 2
D) 4
The number of (H2S) moles that is required to react with one mole of Cr2O72- in acidic
medium according to:
Cr2O72- + H2S ⇌ Cr3+ + S
is:
A) 1
C) 3
7.
B) 0.056 M
D) 0.500 M
As far as the oxidation number of (Cl) is corrected, one of the following orders is correct:
1) OCl- > O2Cl- > O3Cl2) O3Cl- < O2Cl- ≤ OCl3) O2Cl- < O3Cl- > OCl4) O3Cl- > O2Cl- > OClA) 1
C) 3
6.
B) 1140.2 mL
D) 877.2 mL
A solution is made by diluting 235 mL of 0.120 M Fe(NO3)3 with water to a final
volume of 0.500 L. The molarity will be:
A) 0.060 M
C) 20025 M
5.
B) C3O2
D) C4O3
Volume of 0.285 M KOH that is needed to give 0.25 mol of KOH is:
A) 97.4 mL
C) 250.0 mL
4.
B) 400 kg
D) 257 kg
B) 1.54 g/L
D) 3.00 g/L
O2 gas was collected over water at 30oC in a 150-mL vessel until the total pressure was 600
torr. What would the volume (in mL) of dry O2 be at STP?.
(Vapor pressure of H2O at 30oC is 31.8 torr)
A) 106.70
C) 101.04
B) 93.45
D) 75.00
9.
According to the reaction:
2 CO(g) + O2(g)  2 CO2
How many milliliters of CO2 measured at 1 atm and 25oC would be produced from the
reaction of 500 mL of O2 measured at STP?.
A) 1091.58
C) 458.05
10.
B) 545.80
D) 916.10
According to the following thermochemical equation:
2 NO(g) + Cl2(g)  2 NOCl(g)
Ho = -77.4 kJ
How much energy evolved (in kJ) as a result of the reaction of 3 g of NO?.
A) 7.74
C) 3.87
11.
B) 15.48
D) 30.96
Diacetylene has a H of of 452 kJ mol-1 and the structure H-C≡C-C≡C-H. What is the
average C≡C bond energy in this molecule given the following information:
4 C(s) + H2(g)  C4H2
-1
BE of C-H = 415 kJ mol
BE of C-C = 348 kJ mol-1
o
H f of C(g) = 715 kJ mol-1 and
H of of H(g) = 218 kJ mol-1
A) 1666 kJ mol-1
C) 610 kJ mol-1
12.
B) 833 kJ mol-1
D) 416.5 kJ mol-1
Among the following reactions, which one (or ones) has (or have) Eo equals to Ho?:
1) 4 NH3(g) + 3 O2(g)  2 N2(g) + 6 H2O(g)
2) SiH4(g) + 2 O2(g)  SiO2(g) + 2 H2O(g)
3) Cu2S(s) + 2 O2(g)  2 CuO(s) + SO2(g)
A) 3 only
C) 2 only
13.
B) 2 and 3
D) 1 and 3
One of the following structures for SF4 is correct:
:F:
:F:
A)
:F
S
:F:
14.
F:
B)
:F
S
:F:
:F:
F:
C)
:F:
:S
F
F:
D)
:F:
Lewis structure of one of the following compounds does not obey octet rule:
1) CCl4
2) CO2
3) PCl3
4) BH3
A) 1, 2
C) 3, 4
B) 2 only
D) 4 only
:F
S
:F:
F:
15.
Which of the following statements is wrong:
A) Any reaction in which H+ transfers from a substance to another is an acid-base reaction.
B) Any proton donor is an acid.
C) Solutions of highly charged metal ions are basic.
D) For oxoacids of the same central atom, the greater the number of oxygen
atoms the stronger the acid.
16.
The conjugate base of HS- is:
A) H2S+
C) H2S
17.
B) S2D) S-
The correct arrangement of heat of vaporization of the following compounds is:
A) C10H22 > C2H6 > CH4 > C3H8.
B) CH4 > C2H6 > C3H8 > C10H22.
C) C10H22 > C3H8 > C2H6 > CH4.
D) C10H22 > CH4 > C3H8 > C2H6.
18.
A solution of 5 g isopropyl alcohol C3H7OH in water has a mole fraction of alcohol
equal to 0.25. The molality of this solution is:
A) 4.2 m
C) 13.5 m
19.
The solubility of oxygen gas in H2O at 20oC and 760 torr is 0.44 g/L; the solubility at
160 torr and 20oC is:
A) 2.09×10-2
C) 9.26×10-2
20.
B) 184.7 g
D) 115.3 g
What is the molecular weight of a solute A, if the osmotic pressure of a solution
containing 10 g/L is 10.0 torr at 23.5oC?.
A) 19075 g
C) 20000 g
22.
B) 7.02×10-2
D) 4.54×10-2
When 10.6 g of a nonvolatile substance is dissolved in 740 g of ether, its boiling point is
raised 0.284oC. What is the molecular weight of the substance? [Kb(ether) = 2.11oC/m]
A) 106.4 g
C) 211.6 g
21.
B) 11.5 m
D) 18.5 m
B) 16500 g
D) 18700 g
A solution containing 1.00 mol of acetone and 1.5 mol of chloroform has a vapor
pressure of 0.329 atm at 35oC. At this temperature, the vapor pressure of pure acetone is
0.453 atm, and the vapor pressure of pure chloroform is 0.388 atm. By comparing the
measured vapor pressure and the calculated one, the above solution is:
A) Endothermic solution
B) Exothermic solution
23.
C) Ideal solution
D) We can’t tell
A system at equilibrium is described by the equation: Heat + SO2Cl2(l ) ⇌ SO2(g) +
Cl2(g)
One of the following sentences is correct.
A) Adding Cl2 will increase heat.
B) The equilibrium will move to the left when we remove Cl2.
C) Increasing the pressure has no effect on this system.
D) Adding catalyst will cool the system.
24.
For the following reaction
2 NH3(g) ⇌ N2(g) + 3 H2(g)
if, Kc = 2.6×10-5 mol2 L-2 at 127oC. Then Kp at the same temperature is:
A) 2.8×10-2 atm2
C) 8.2×10-4 atm2
25.
For the following equilibrium :
2 N2(g) + O2(g) ⇌ 2 N2O(g)
-18
The Kc = 6.5×10 at a certain temperature. If 0.04 mol N2 and 0.06 mol O2 are placed in 1.0
L container and allowed to react, what will be the equilibrium concentration of N2O:
A) 1.8×10-8 M
C) 2.5×10-11 M
26.
B) 3.25×10-4
D) 4.2×10-7
When 3.16×10-5 mol of substance is dissolved in 1.00 L solution, the pH became 6.5.
The substance is a:
A) strong acid
C) weak acid
29.
B) 0.1 , 0.1
D) 0.2 , 0.2
0.1 mole of aspirin (acetyl salicylic acid) C8H7O2COOH is dissolved in 1.0 L solution. If
the pH = 2.244, the value of Ka will be:
A) 1.4×10-5
C) 3.2×10-8
28.
B) 1.0×10-12 M
D) 8.3×10-10 M
The equilibrium constant Kc for the following reaction:
acid + alcohol ⇌ ester +
water
equal 4. If we start with initial concentration of ester and water equal to 0.3 mol L-1. Then
the equilibrium concentration of the acid and alcohol are respectively:
A) 0.15 , 0.15
C) 0.3 , 0.3
27.
B) 2.1×10-3 atm2
D) 2.6×10-5 atm2
B) strong base
D) weak base
Blood is buffered mainly by the presence of HCO3- and H2CO3 (Ka = 4.2×10-7).
Knowing that pH of the blood is 7.4, the ratio:
A) [HCO3-] = 2.00 [H2CO3]
C) [HCO3-] = 0.50 [H2CO3]
B) [HCO3-] = 10.55 [H2CO3]
D) [HCO3-] = 5.00 [H2CO3]
30.
If 0.1 mole of HCl was added to a 1.0 L buffer solution containing 0.45 mol of acetic
acid, HC2H3O2 and 0.55 mol of sodium acetate, NaC2H3O2, the pH will be:
(Ka =
-5
1.8×10 )
A) 4.85
B) 4.65
C) 0.55
D) 1.8×10-5