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TALIGAMAN NATIONAL HIGH SCHOOLButuan City

SCIENCE IIIFOURTH PERIODICAL EXAMINATION

(S.Y. 2011-2012)

NAME: __________________________________ YR.&SEC. ______________ SCORE: ____Multiple Choice. Choose the letter of the correct answer and write it on the space provided.

____ 1. According to Kinetic Molecular Theory, kinetic energy of a substance *

a. increases during fusion c. increases with increasing temperatureb. decreases during conduction d. decreases with increasing temperature

_____ 2. Which of the following assumptions of Kinetic Molecular Theory of gases is correct?a. Gas particles strongly attract each other.b. Gas particles travel in curved path.c. The volume of gas particles prevents random motion.d. Energy may be transferred between colliding particles.

____ 3. The average kinetic energy of the molecules is proportional to the temperature of the gas in Kelvin. Temperature in Kelvin can be converted into degrees Celsius; by

a. dividing 273 from the temperature c. subtracting 273 from the temperatureb. multiplying 273 from the temperature d. adding 273 from the temperature

______4. What happens to the average kinetic energy of ideal gas molecules when the volume of gas is increased by decreasing the pressure at constant temperature?

a. Kinetic energy increase. c. Kinetic energy decreasesb. No change in kinetic energy d. Kinetic energy changes by a factor of 0.5

______ 5. The following are Postulates of Kinetic Molecular Theory.I. Gas molecules move in straight lines in all directions.II. Collisions with other molecules changes the direction of motion.III. Gas molecules occupy all regions of the container.

Why does a gas will evenly fill any container of any shape?a. I only b. II only c. III only d. I, II and III

_____6. Which of the following does not describe a gas?a. compressible c. no fixed volume;b. widely separated d. higher density

______7. In comparison to solid and liquids, gases have______densities due to the amount of spacebetween the molecules.

a. no b. lower c. high d. higher

_____ 8. Why do gases have neither definite shape nor volume?a. The attractive forces between molecules of gas are negligible.b. The attractive forces between molecules of gas are less due 1 o its restricted looseness.c. The attractive forces between molecules of gases are strong's*.d. The attractive forces between molecules of gases are localized in a certain area.

______9. Why do you feel the wind when it blows?a. Gas molecules move with a fixed vibrating motion.b. Gas molecules are in very rapid motion.c. Gas molecules are just touching but still move quite freely.d. Gas molecules slip fast each other.

_____10. What is the process of spreading out spontaneously to uniformly occupy a space?

a. expansion b. volume c. diffusion d. pressure

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_____11. At the same temperature and pressure, which gas will diffuse through air at the fastest rate?

a. H2 b. O2 c. CO2 d. C02

____ 12. A gas of unknown identity diffuses at the rate of 16.0 m/s in diffusion apparatus in which a second gas whose molecular weight is 28.00 diffuses at the rate of 24.2 m/s. Calculate the molecular weight of the first gas.

a. 46.1 g/mole b. 14.6g/mole c. 64.1 g/mole d. 41.6g/mole

____ 13. Gases A and B form a pink color upon contact with solution C. The two gases were each allowed to diffuse on a paper wet with solution C in a tube of fixed length. It was observed that it took one minute for Gas A to form a pink color, and two minutes for Gas B. What do these results suggested?

a. Gas A has greater particle mass than Gas B.b. Gas A has lesser particle mass than Gas B.c. Gas A particle travel more slowly than Gas B.d. Gas A and B have the same particle mass.

____ 14. Which of the following will substantially change in volume if the pressure exerted on it is doubled?a. gas b. liquid c. solid d. all of these

____ 15. A syringe with a sealed tip contains 0.1 g of gas at room temperature. As the plunger of the syringe is pushed down, what does not happen?

a. The pressure of the gas increases. c. The molecules some closer to each other,b. The molecules move faster. d. The volume of the gas decreases.

____ 16. A sample of hydrogen has a volume of 1.0 liter at a pressure of 760 torr. If the temperature is kept constant and the pressure is raised to 860 torr, the new volume, in liters, will be equal to_______.

a. 760 b. 860-760 c. 860 d. 860 + 70 860 760

____ 17. If the pressure of a confined gas at constant temperature is tripled, what will happen to thevolume?

a. the volume will be tripledb. the volume will be reduced to one third the originalc. the volume will remain unchangedd. the volume will be doubled

____ 18. The volume of a mole of any ideal gas varies ________ at constant pressure.a. directly with the radius of glass moleculesb. inversely with the radius of the gas moleculesc. directly with the Kelvin (absolute) temperatured. inversely with the Kelvin (absolute) temperature

____ 19. A child’s balloon is filled with helium to give a volume of 5.0 L, in an air conditioned store at 21°C. The child takes the balloon outdoors where the air temperature is 38°C. What happens to the balloon?

a. the volume increases c. the volume decreasesb. there is no change in the volume d. the pressure will change

____ 20. The volume of a gas is 400 mL at - 20 °C. If the pressure of the gas is held constant and the temperature is changed to 40 °C, the final volume of the gas will be equal to 400 mL multiplied by_________.

a. 293 b. 253 c. 313 d. 313 313 313 293 253

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____ 21. At constant pressure, which curve below shows the relationship between the volume of an ideal gas and its absolute temperature?

a. A b. B c. C d. D

DVolume in C

Liters

BA

Temperature in Kelvin

____ 22. The ratio of pressure P to temperature T is the same under all conditions as long as volume V and amount of gas n do not change. This law refers to

a. Boyle’s Law c. Gay - Lussac’s Lawb. Charles’ Law d. Avogadro’s Law

____ 23. A sealed metal container was heated at constant volume and a c anstant amount of gas. What happened when pressure increased?

a. boiling point is the same c. boiling point inci easesb. boiling point decreases d. boiling point can not be determined

____ 24. If the volume of one mole of gas molecules remains constant, lowering the temperature will make the pressure?

a. increase b. increase then decrease c. decrease d. decrease then increase

____ 25. Given the equation P1V1 = P2V2? , which of the following is the formula for final temperature?T1 T2

a. T2 = P2 x V2 x T1 c. T2 = P1 x V1 x T1

P1 V1 P2 V2

b. T2 = P1 x V2 x T1 d. T2 = T1 x V1 x T1

P2 V1 P1 P2

____ 26. Which of the following laws made up the combined gas law ?a. Boyle’s Law, Gay - Lussac’s Law and Avogadro’s Lawb. Charles’ Law, Avogadro’s Law and Graham’s Lawc. Gay - Lussac’s Law, Charles Law and Boyle’s Lawd. Graham’s Law, Ideal Gas Law and Chr'es’ Law

____ 27. What will happen to the temperature of an ideal gas if its pressure is halved and its volume is quadrupled?

a. It will be halved c. It will be quadrupledb. It will be doubled d. It will increase by a factor of 8

____ 28. Which of the following indicates the amount of gas particles?a. 10.0 L b. 760 torr c. 273 K d. 3.0 mole of He

____ 29. Hazel is blowing a balloon and its volume increases. What will happen if it is punctured?a. volume increases as some air leaks out c. volume decreases as some air leaks outb. volume increases as more air is added d. volume decreases as some air is added

____ 30. At a certain temperature and pressure, a gas containing 1.0 mole has a volume of 5.0 mL.What is the new volume after 2 more moles are added to it?a. 2.0 mL b. 3.0 mL c. 10.0 mL d. 15.0 mL

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____ 31. A mole of an ideal gas occupies a volume of 22.4 liters ata. 273 K and 760 torr c. 273 K and 0 torrb. 760 0 C and 273 torr d. 0 °C and 273 torr

____ 32. How many moles of an ideal gas will occupy 44.8 liters at standard temperature and pressure? a. 1.0 b. 2.0 c. 22.4 d. 44.8

____ 33.. What pressure will 500 mL of gas exert at 27 °C if there are 3 moles of the gas present?R = 0.082 atm.L

mole.K

a. 0.0133 atm b. 13.28 atm c. 147.6 atm d. 493.9 atm

____ 34. What is the pressure of a mixture of CO2, SO2 and H2O gases, if each has a partial pressure of 250 torr?

a. 250 torr b. 500 torr c. 750 torr d. 1000 torr

____ 35. In a gaseous mixture at 20 °C the partial pressure of the components are as follows: hydrogen 200 mm Hg, carbon dioxide 150 mm Hg, methane 320 mm hg and ethylene. If fits total pressure is 775 mm Hg, what will be the partial pressure of ethylene?

a. 95 mm Hg b. 105 mm Hg c. 115 mm Hg d. 125 mm Hg

____ 36. A 200 cm3 flask contained oxygen at 200 mm Hg pressure, and a 300 cm3 flask containednitrogen at 100 mm Hg pressure. The two were then connected so that each gas failed their combined volume. Assuming no change in temperature* what was the total pressure of the final mixture?a. 110 mm Hg b. 120mmHg c. 130 nun Hg d. 140mmHg

____ 37. Cans used for deodorants, insecticides and spray cans contain warnings against storage above120 C. What is the best explanation for this?a. These cans can be recycled. c. These cans can be sold for extra money.b. These cans might explode. d. These cans can be used as storage.

____ 38. What happen to one’s lung when one relaxes?a. Volume of lungs decreases causing air pressure in lungs to be greater than atmospheric

pressure.b. Volume of lungs increases causing air pressure in lungs to be greater than atmospheric pressure.c. Temperature in lungs decreases causing air pressure in lungs to be greater than atmospheric

pressure.d. Temperature in lungs decreases causing air pressure in lungs to be greater than atmospheric

pressure.

____ 39. Pressure cooker saves time. What happen when one cooks food in it?a. Water in the pressure cooker will boil at lower temperature than 100 °C and food cooks faster.b. Water in the pressure cooker will boil at lower temperature than 100 °C and food cooks slower.c. Water in the pressure cooker will boil at higher temperature than 100 °C and food cooks slower.d. Water in the pressure cooker will boil at liigher temperature than 100 °C and food cooks faster.

____ 40 . What happens when a reaction takes place endothermically?a. The temperature of the system drops.b. The temperature of the surroundings drops.c. The temperature of the surroundings rises.d. The temperature of the surroundings is constan t.

____ 41. Which of the following changes is exothermic?

a. steaming of fish c. melting of iceb. photosynthesis in plants d. burning of alcohol

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____ 42. Methane + oxygen —> carbon dioxide + water

Which of the following is not true about this reaction?a. it is a combustion reaction c. it gives out lightb. it is endothermic d. it is the burning of fossil fuel

____ 43. In industry, catalysts are added to chemical reaction in order to

a. increase the temperature of reaction c. increase the amount of products formedb. enable the products to be separated d. increase the speed of formation of products

____ 44. Given the reaction: A (g) + B(g) —► C(g)

As the concentration of A (g) increases, the frequency of collisions of A(g) with B(g)a. decreases b. remains the same c. increases d. cannot be determined

____ 45. Why the speed of some chemical reactions is increased when the surface area of reactants is increased?

a. density of reactant particle is increased b. concentration of the reactants is increasedc. reactant particles are exposed more to a possible collisiond. electrical conductivity of reactant particles is altered

____ 46. Under which conditions will the rate of chemical reaction always decrease?

a. Concentration of reactants decreases and temperature decreases.b. Concentration of reactants decreases and temperature increases.c. Concentration of reactants increases and temperature decreases.d. Concentration of reactants increases and temperature increases;

____ 47. Beaker A contains a 1 gram piece of zinc and beaker B contains 1 gram of powdered zinc. If 100 mL of 0.1 M HC1 is added to each of the beakers, how does the rate of reaction in beaker A compare to the rate of reaction in beaker B?

a. rate in A is greater due to smaller surface area of zincb. rate in A is greater due to larger surface area of zincc. rate in B is greater due to smaller surface area of zincd. rate in B is greater due to larger surface area of zinc

____ 48. To avoid food spoilage, one should _____________

a. place food in a refrigerator c. place food in the cabinetb. cover the container tightly d. feed it to the dog

____ 49. Which of the following does not prevent growth of microorganisms on food?

a. curing of meat using sodium nitrate c. use of sulfur dioxide to bleach in dried fruitb. adding more salt to fish and sundry d. washing fruits

____ 50. Plant growth is a common chemical reaction. Photosynthesis transforms__________and______ into sugar and oxygen with the presence of sunlight.

a. CO2 and O2 c. CO2 and N2

b. H20 and C02 d. H20 and 02