11. Fruit is canned while it is steaming hot because a. the added pressure inside helps to seal the jars. b. the fruit stays hot longer in sealed jars. c. the atmospheric pressure will be greater than the inside pressure when the jars cool. d. the lids loosen as the fruit cools.
NMAT CHEMISTRY SIMULATIONS (MOCK 1) DIRECTIONS: Select the best answer to each of the following questions and blacken the appropriate space on your answer sheet. 1. Which gas contains molecules with the highest average highest average kinetic energy? a. Gas A: 2 moles at 273 K b. Gas B: 1 mole at 293 K c. Gas C: 1 mole at 500 K d. Gas D: 2 moles at 546 K
12. When 2.0 grams of methane are burned in a bomb calorimeter containing 2000 grams of water, it causes the temperature of the water to rise by 13.300C. What is the molar heat of combustion of methane? Cp (H2O) = 4.18 Joule/g 0C. a. 111 kJ c. 13.3 kJ b. 888 kJ d. 8.88 kJ
2. Which is most effective in changing a gas into a liquid? a. Reduce the temperature and pressure. b. Increase the temperature and pressure. c. Reduce the temperature and increase the pressure. d. Increase the temperature and reduce pressure.
13. Which of the curves show the relationship between the volume of an ideal gas (at constant pressure) and its temperature in degrees Kelvin?
3. Doubling the initial pressure under which 100 ml of a gas was confined causes the volume of the gas to a. double b. remain the same c. decrease very slightly d. first increases then decreases 4. What is the percentage of chromium in the compound, potassium dichromate, K 2Cr2O7? (At. Wt. K=39, Cr=52, O=16) a. 17% b. 35% c. 3.5% d. 52%
a. 1
b. 2
c. 3
d. 4
e. 5
14. If I dilute 5 mL of 0.15 M NaCl to a final volume of 5 L,
what’s the final concentration of NaCl?
5. The molecular weight of a substance is 128 and its equivalent weight in a particular reaction is 32. A 2.0-N solution of this substance will have a molarity: a. 4.00 M b. 8.00 M c. 0.50 M d. 0.25 M
a. 0.00015 M b. 15000 M
c. 0.0015 M d. 0.015 M
15. Nuclear fission: process in which a heavy nucleus splits into lighter ones. What is the value of n?
+
6. What is the [ ] in a 0.005 M solution of NaOH? a. 5 x 10−3 b. 2 10− c. 2 10− d. 5 10 −
7. Mercury is better suited than water for use in a barometer chiefly because mercury a. boils at a lower temperature b. has high density and evaporates very little c. is cheap d. is non-poisonous
a. 2
3 9 → b. 1
4 6
c. 3
9 36 ? d. 4
16. At constant pressure, which curve best shows the relationship between the volume of an ideal gas and its absolute temperature?
Use the following balanced equation for nos. 8 to 10: 2 () + 5 (g) 2 (g) + HEAT 8. An increase in the amount of will shift the equilibrium to what direction? a. to the right c. not at all b. to the left d. reversible 9. An increase in pressure will shift the equilibrium to what direction? a. to the right c. no effect b. to the left d. reversible
a. A
10. A decrease in temperature will ______. a. shift the equilibrium to the right b. both reaction are affected c. shift the equilibrium backward d. have no effect
1
b. B
c. C
d. D
17. The vapor pressure curves 3 liquids, A, B, and C are shown in the graph. What is the correct interpretation of the
23. Crystals which lose water on exposure to air are a. hygroscopic c. efflorescent b. anhydrous d. deliquescent
graph at 55˚C and 760 mm of Hg?
24. Which of the following compounds will give a pH < 7? a. CaI2 b. MgSO4 c. KClO d. NH4NO3 25. Which of the following compounds will give an alkaline solution? a. CaI2 b. MgSO4 c. KClO d. NH4NO3 26. Two liquids which are immiscible are water and a. H2SO4 c. CCl4 b. ethyl alcohol d. methyl alcohol
a. All three species are liquid. b. A and B are gaseous and C is a liquid. c. A is gaseous, B and C are liquid. d. All three species are gaseous.
27. Alcohol is very soluble in water because both compounds a. are liquids b. are ionic c. possess molecules that can link hydrogen bonds d. are non-polar
18. A 5 liter bulb and a 3 liter bulb are attached by a closed stopcock. The larger bulb contains helium gas at 540 torr, while the smaller bulb contains neon gas at 320 torr. What is the pressure in the larger bulb after the stopcock is opened and equilibrium is achieved?
a. 540 torr.
b. 338 torr.
c. 320 torr.
28. This graph illustrates the observed phenomena of X and Y during dissolution. Which is a correct interpretation of the graph?
d. 340 torr.
19. At 25˚C, 100 ml of saturated solution of NaCl is in equilibrium with 1.0 gram of solid NaCl. The concentration of the solution will be changed most when: a. 80 ml of water are added to the solution b. additional solid NaCl is added to the solution c. the pressure of the solution is increased
a. The dissolving of Y is an endothermic process. b. The dissolving of X is an exothermic process. c. At a given temperature, Y is more soluble than X. d. Increasing the temperature decreases the solubility of Y.
d. the temperature of the solution is decreased 5˚C.
29. The activation energy, Ea of a certain endergonic reaction is 25 kcal. The Ea for the reverse reaction is: a. equal to 25 kcal c. less than 25 kcal b. greater than 25 kcal d. none of these
20. A crime lab analyzes two samples of a drug, sample A and sample B. Sample A is crystalline. Several microscopic samples taken from different points in Sample A are indistinguishable; all properties of the mat erial seem uniform. Sample B has a slightly different color than sample A. Chromatographic techniques resolve sample B into separate components. Which of the following conclusions are valid? 1. Sample A is a pure substance. 2. Sample B is a mixture. 3. Sample A is not a heterogeneous mixture. a. 2 and 3 c. 1 and 2 b. 1 and 3 d. all are valid
30. Which curve represents the relationship between solubility and temperature of most solids, such as KNO3, in water?
21. Raising the temperature of a solution of a gas in a liquid a. lowers the equilibrium concentration of the solute b. lowers the speed of the solute molecules c. lowers the speed of the solvent molecules d. increases the miscibility of the solute and solvent. 22. In general, the solubility of gases in water a. decreases as the pressure increases b. is constant for all types of gases c. is not affected by temperature change d. decreases as the temperature increases
2
a.
b.
c.
d.
31. Carbon tetrachloride is a covalent compound with four non-polar bonds symmetrically distributed. Consequently, it is a. a weak electrolyte b. a strong electrolyte c. a conductor of electricity without being dissolved in water d. a non-polar molecule
37. NaNO3 conducts the electric current when melted, but not in solid state because a. it is covalent when solid, but ionic when melted. b. ionization of the salt depends upon the temperature. c. the mobility of the ions is increased by heating. d. it contains more ions in the melted state than in the solid state.
32. Using Markovnikov’s rule in the hydration of alkenes, what is the product of:
38. Because of a hydrogen bond, the hydrogen atom of one water molecule may be a. weakly attracted to the oxygen of a second water molecule b. weakly attracted to the hydrogen of a second water molecule c. strongly attracted to the oxygen of a second water molecule d. strongly attracted to the hydrogen of a second water molecule
CH3CH2CH2CH=CH2 + HBr a. CH3CH2CH2CHBrCH3 b. CH3CH2CH2CH2CH2Br
c. CH2BrCH2CH2CHICH3 d. CH3CHBrCH2CH2CH3
33. Oxygen gas (Molecular weight = 32) diffuses at the rate of 10 mL/min. Under the same conditions of temperature and pressure, how fast will hydrogen (molecular weight = 2) diffuse? a. 20 mL/min c. 160 mL/min b. 40 mL/min d. 10 mL/min
39. According to the modern theory, when sodium chloride is dissolved in water, the process that occurs a. causes the water to break down into ions b. results in free, unattached Na+ and Cl- ions in water c. produces sodium hydroxide and hydrochloric acid d. produces hydrated sodium and chloride ions
34. Compound X rapidly decolorizes in a solution of bromine in CCl4. When X is subjected to ozonolysis, two products are formed, namely butanone and propanal. What is the structure of X? a. 3 = 3 b. 3 = 3
40. The water molecule is frequently referred to as the water dipole because a. ionic bonding holds the molecule together. b. the polar covalent bods are unsymmetrically distributed. c. the non-polar bonds are ionic. d. the covalent bonds are symmetrically distributed.
3 c. 3 d. 3 = 3 3
41. The boiling of a pure substance is defined as the temperature at which a. the kinetic energy of the molecules begins to increase. b. the vapor pressure equals the external pressure. c. the liquid phase can be completely evaporated. d. the molecules of the substance break apart.
35. If each of the following is resonance stabilized, what will be the correct arrangement of the compounds according to their relative degree of aromatic character?
Furan
thiopene
42. Which of the following salt solutions would have the lowest freezing point? a. 0.1 M Na3PO4 c. 0.1 M NaOH
pyrrole
b. 0.1 M Na 2SO4
a. thiopene > pyrrole > furan b. furan > pyrrole > thiopene c. furan > thiopene > pyrrole d. thiopene > furan > pyrrole
43. A solution is saturated at 30˚C, filtered, and cooled to
20˚C. No precipitation occurs. The solution is a. supersaturated b. miscible
36. Rank the following alcohols from least acidic to most acidic in ascending order (least acidic to most acidic):
a. A, B, C
b. C, B, A
d. 0.1 M KNO3
c. B, C, A
c. unsaturated d. electrolytic
44. Which of the following statements are correct? I. Carboxylic acids have lower boiling points than alcohols of comparable molecular weight because both the carbonyl oxygen and the hydroxyl group can engage in hydrogenbond formation. II. Carboxylic acids have greater acidity compared with alcohols because electron delocalization can take place in the carboxylate ion. III. Trifluoroacetic acid (CF3COOH) is less acidic than acetic acid (CH3COOH) IV. Grignard reagent is nucleophilic and when added to CO2 carboxylic acid is formed after acidification. a. I and III c. I and IV b. II and IV d. II and III
d. A, C, B
3
45. What type of reaction is involved when: ethene + hydrogen ethane a. hydrogenation c. fermentation b. esterification d. substitution →
46. In order to synthesise butylpropanoate you would use: a. C3H7OH and CH3COOH b. C4H9OH and CH3COOH c. C3H7OH and C3H7COOH d. C4H9OH and C2H5COOH The half-life of a radioactive substance is the time required for half of the amount of the substance to change to other substances. The half-life of radium-226 is 1,600 years: 47. How long will it take for 2.0 g. sample of radium-226 to become 0.5 gram of the same sample substance? a. 1,600 years c. 3,200 years b. 2,400 years d. 4,000 years 48. After 7,800 years, how many grams of the element would be left? a. 1.0 g b. 0.0625 g c. 0.25 g d. 0.125 g 49. What is the basis for the Lewis basicity of amines? a. availability of amines b. release of OH groups c. acceptance of lone pairs d. capacity to abstract acidic hydrogen 50. You want to remove as much CO2 gas as possible from a water solution. Which of the following treatments would be most effective? a. cool the solution c. compress the solution b. filter the solution d. boil the solution
4
