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Released Test Questions

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1 Released Test Questions 2000 - 2009
Chemistry Scientific Investigation Released Test Questions

2 Measurements should be taken using the same balance.
The following data are obtained in the laboratory: (a) The mass of a clean, dry 250 mL beaker (b) The mass of the same beaker containing an unknown quantity of magnesium sulfate. The mass of the magnesium sulfate is obtained by subtracting (a) from (b). Which of the following will provide the most accurate results? Measurements should be taken using the same balance. The temperature of the room must remain constant. The barometric pressure should be recorded. A calculator should be used to subtract (a) from (b).

3 Many reactions are taken to completion by heating the reaction mixture in a test tube. Each of the following would be a safe practice except — heating the test tube gently to prevent the solution from boiling over pointing the test tube away from others so that no one is injured placing a stopper in the test tube to prevent gas from escaping holding the test tube with test tube clamps to avoid touching hot objects

4 A student wants to study the effects of volume on gas pressure. During his experiment, he recorded the data below. How could he now study the effects of temperature on gas pressure? Vary the temperature but keep the gas volume constant Vary the volume of the gas only Vary the pressure and temperature of the gas Vary the temperature and volume of the gas

5 2000.4. Which salt’s solubility in water is least affected by temperature?
NaClO3 KNO3 KBr NaCl

6 Use the same amount of catalyst in all trials Keep all tubes at 18⁰C Keep the reaction time constant Decrease the quantity of reactants

7 2000. 6. A student massed a piece of iron on a balance
A student massed a piece of iron on a balance. The most sensitive beam was marked off in 0.1 g intervals. The student reported the iron’s mass as g. Which of the digits in the measurement is estimated? 1 2 3 4

8 A student measured the temperature of a boiling solution and found it to be 56.0⁰C at standard pressure. The theoretical temperature of that boiling solution is 55.0⁰C. What is the percent of error in the student’s measurement? 18% 1.8% 0.18% 0.018%

9 2000.8. How many significant digits are in 0.003450?
6 7

10 2000. 9. A 0. 500 L solution of 6 M HCl has to be made
A L solution of 6 M HCl has to be made How much 12 M HCl is needed? 0.250 L B 2.50 L C 25.0 L D 2500 L

11 2000.10. Which graph best represents the above generalization?
1. Picture Choice 1 Picture Choice 2 Picture Choice 3 Picture Choice 4 2. 3. 4.

12 To remove the sand first and then the salt from a mixture of sand and salt water, one combination of techniques you could use would be to first — evaporate and then distill evaporate and then condense filter and then evaporate filter and then condense

13 Formula 1 Formula 2 Formula 3 Formula 4
The element chlorine exists as two naturally occurring isotopes. Cl-35 occurs 75% of the time and Cl-37 occurs 25% of the time. Which of the following calculations should be used to calculate the correct average atomic mass of chlorine? 1. Formula 1 Formula 2 Formula 3 Formula 4 2. 3. 4.

14 The mass of an object was recorded as 9.93 g, 9.90 g, and g, using an electronic analytical balance. What is the average of these three masses expressed to the correct number of significant figures? 9.9 g 9.95 g 10.0 g 10.00 g

15 0.75 g 1.75 g 2.25 g 2.50 g

16 A student wanted to calculate the formula for hydrated copper sulfate. After careful massing, she heated the compound to remove the water. She calculated the formula to be CuSO4 · 4H2O. The actual formula was CuSO4 · 5H2O. What is the most likely source of analytical error in the student’s experiment? The water was not completely evaporated from the compound. The actual mass of the anhydrous CuSO4 was less than the measurement. The CuSO4 reacted with element copper. The atmospheric pressure prevented complete reaction.

17 2001.19. What is the percentage of aluminum in aluminum oxide (Al2O3)?
47% 48% 53% 54%

18 1 g/mL 0.8 g/mL 0.81 g/mL 0.821 g/mL

19 A student must make a 3 M acid solution using a 5 M acid solution. Which of these is the safest way to make the solution? Slowly pour the 5 M acid into water Slowly add water to the 5 M acid solution Mix half the acid with water, then add the remaining water Mix half the water with the acid, then add the remaining acid

20 What is the first step that should be taken when a caustic chemical gets in to a person’s eye? Identify the chemical Call for an ambulance Flush the affected area with water Apply a neutralizing agent

21 2001. 38. Which of these shows a volume of 1
Which of these shows a volume of liters expressed in milliliters? 125 mL 12.5 X 101 mL 1.25 X 102 mL 1.25 X 103 mL

22 Test tube Beaker Flask Graduated cylinder
Which of the following pieces of glassware can be used to measure the volume of a liquid with the greatest accuracy? Test tube Beaker Flask Graduated cylinder

23 Most gases have the property of becoming increasingly soluble in a liquid as the temperature of the liquid decreases. Which graph shows this relationship? F G H I

24 2002.5. How is 0>00124 expressed in proper scientific notation?
1.24 1.24 X 103

25 Trial Mass 1 26.5 2 26.4 3 Accuracy Continuity Precision Reliability
A student measures the mass of a piece of copper three times and records the results in the following table. The actual mass of the copper is 28.7 grams. Which of the following is demonstrated in the student’s data? Accuracy Continuity Precision Reliability Trial Mass (grams) 1 26.5 2 26.4 3

26 The mass and the volume were multiplied
To determine the density of corn syrup, a student poured 3.0 mL of the liquid into a 10.0 mL graduate cylinder and massed the cylinder and contents. He determined the density to be 10.5 g/cm3. The accepted value for the density of corn syrup is 1.38 g/cm3. The most probable cause of error was that__ The mass and the volume were multiplied The mass of the cylinder was included in the density formula The graduate cylinder accuracy is only +0.5 mL The mass and volume were inverted in the density formula

27 A chemical engineer for a fertilizer company is determining the most efficient way to produce ammonia. The engineer carries out the Haber reaction under four different conditions. According to these data, which procedure gave the greatest percent yield? A B C D

28 Color Weight Form Taste
When examining the physical properties of an unknown substance, which of the following characteristics is unsafe to observe? Color Weight Form Taste

29 2002. 34. The density of an unknown metal was determined to be 2
The density of an unknown metal was determined to be 2.85 g/mL. The actual density was 2.70 g/mL. What is the percent error in this determination? 0.056% 0.15% 5.6% 94.4%

30 A student designed this experiment to study the effects of a catalyst on a reaction. Which trial serves as the experimental control? 1 2 3 4

31 Wipe it off with a paper towel Let it air dry
A student spills diluted acid solution on his hand He should . . . Wipe it off with a paper towel Let it air dry Apply a base solution to neutralize it Rinse it off with running water

32 Beaker Erlenmeyer flask Graduated cylinder Test tube
For an experiment, 9.7 Ml Of HCl are needed. What is the best instrument to use for measuring the volume? Beaker Erlenmeyer flask Graduated cylinder Test tube

33 2003. 2. A student used this ruler to measure the length of a nail
A student used this ruler to measure the length of a nail. The length of this nail according to the precision of the ruler is-- 3.5 cm 3.55 cm 3.7 cm 3.75 cm

34 These data show repeated measurements of the same object which has a known mass of 5.38 grams. Which measurement is most accurate? 1 2 3 4 Measurement 1: 5.2 g Measurement 2: 5.4 g Measurement 3: 3 g Measurement 4: g

35 Rinse the hand in a concentrated base. Rinse the hand in running water
If a student’s hand is accidentally exposed to an acidic solution, what should be done? Rinse the hand in a concentrated base. Rinse the hand in running water Wrap the hand in paper towels Cover the hand with oil.

36 A student was instructed to carry out an experiment that illustrates the law of conservation of mass. The teacher indicated that the experiment should be carried out three times. The student plans to report the average of the three results. What can the student do to maximize the reliability of the data collected? Report the result that came closest to the class average. Conduct each trial using the same balance. Report the average of the two most similar values only. Perform each of the trials on different days.

37 At a constant volume, the pressure of a gas will increase as the temperature increases. Which of the following graphs shows that relationship? F G H J

38 2003.33. Which salt is most soluble in water at 90°C?
NaClO3 KNO3 KBr NaCl

39 2003. 35. A student uses a mortar and pestle to crush 1
A student uses a mortar and pestle to crush 1.0g of marble chips and places them into a test tube. A whole 1.0g marble chip is placed into a second test tube, and 5.0mL of 6 M HCl is added to each test tube. The bubbling speed of the produced CO2 gas is noted. This experiment is designed to study the effect of the --- Introduction of a catalyst on reaction rate Type of introduced acid on reaction rate Surface area of a reactant on reaction rate Temperature of a reactant on reaction rate

40 When CuSO4·5H20 is heated in a crucible, there is a loss of water. How should a student determine the amount of water lost? Subtract the mass of the CuSO4 from the mass of CuSo4·5H20 Subtract the mass of the CuSo4·5H20 from the mass of CuSo4 Add the masses of CuSO4·5H20 and CuSo4 Multiply the masses of CuSo4·5H20 and CuSO4

41 Mass the steel and report its density in g/cm3
A student wanted to obtain a very accurate value for the volume of a piece of steel. He filled a 100.0cm3 graduated cylinder to the 50.0 cm3 mark with water. After he carefully dropped the steel into the cylinder, the water level rose to the 55.6 cm3 level. He reported the volume of the steel as 5.6 cm3. How could the student improve the reliability of his analysis? Report the volume as 56 mm3 Fill the graduated cylinder to the 70.0 cm3 mark before adding the steel Mass the steel and report its density in g/cm3 Repeat the measurement many times and report an average value

42 10.0 mL graduated cyclinder
If a student needed to obtain 8.0 mL of a liquid for an experiment, the appropriate piece of laboratory equipment to use would be a — 50 mL beaker 1.0 mL pipet 50 mL flask 10.0 mL graduated cyclinder

43 To produce a variety of results To include another variable
Which of the following best describes why an experiment should be repeated? To organize the date To produce a variety of results To include another variable To verify the observed results

44 The graph shows the rate of a certain reaction as a function of temperature. According to the graph, in order to double the rate of the reaction at 20C, the temperature must be increased by approximately — 10°C 20°C 30°C 40°C

45 Flammability Health Reactivity Contact
If a lab group were using hydrochloric acid to perform a substitution reaction, which precaution would not be a concern? Flammability Health Reactivity Contact

46 Precise but not accurate Accurate but not precise Accurate and precise
A student obtained these data after measuring the mass of an object three different times. If the true value of the object’s mass is g, these data are best described as — First measurement: g Second measurement: g Third measurement: g Precise but not accurate Accurate but not precise Accurate and precise Neither accurate nor precise

47 A team of chemistry students made the above measurements and density calculations of the same type of material. The accepted value (true value) of the density of the material is 5.72 g/cm3. Which trial has the least amount of absolute error? 1 2 3 4

48 Chromatography Filtration Decanting Distillation
The figure shows an experimental setup used to separate the components of a colored ink sample. Which of the following describes this laboratory techniques? Chromatography Filtration Decanting Distillation

49 Filtration Extraction Distillation Crystallization
Which basic lab technique involves the separation of a mixture’s components through differences in particle size? Filtration Extraction Distillation Crystallization

50 Decrease the pressure by 80 kPa Decreases the pressure by 160 kPa
The graph shows the pressure of an ideal gas as a function of its volume. According to the graph, increasing the volume from 100 mL to 150 mL - Decrease the pressure by 80 kPa Decreases the pressure by 160 kPa Increases the pressure by 80 kPa Increases the pressure by 160 kPa

51 2004.50. How should 0.000365 be expressed in proper scientific notation?
3.65 3.65 x 10-4

52 2005. 5. The reaction times for three trials of an experiment are 90
The reaction times for three trials of an experiment are 90.3, 90.2, and 90.5 seconds. Which average time is expressed using the correct number of significant figures? 90.3 90.33 90 90.333

53 2005.10. What is the name of the lab equipment shown?
Watch glass Crucible Beaker Evaporating dish

54 The melting point of a white solid substance was determined in four repeated trials to be 56.0C, 55.0C, 57.5C, 55.5C. What temperature should be reported as the melting point as a result of these trials? 55.0°C 55.5°C 56.0°C 57.5°C

55 Bromocresol green Indigo carmine Neutral red Phenolphthalein
Which is the best indictor for giving a color change at the equivalence point? Bromocresol green Indigo carmine Neutral red Phenolphthalein

56 Methyl mercury, found in some stream sediments, is highly toxic to animal life. Using the graphed results of the study shown, the best analysis of the data reveals that the methyl mercury concentration in the stream sediment is - steadily increasing, accelerating in the fall of each year increasing overall but reaches a minimum in the winter Constantly declining throughout each month of the year Decreasing but reaches a maximum at the end of summer

57 2005.26. What is the mole ration of C4H10 to CO2 in the reaction shown?
1:4 2:13 4:5 13:8

58 What is a possible cause of a large percentage of error in an experiment where MgO is produced from the combustion of magnesium? Not all of the Mg has completely reacted. The same balance was used throughout the experiment The students were carefully in their measurements. The students were careful not to spill the contents.

59 2005.42. The volume of Object X is approximately -
20mL 25mL 30 mL 35 mL

60 2005.44. How many liters are equivalent to five milliliters?

61 2005. 45. The following data were collected
The following data were collected. The volume of the gas is known to be 2.20 L. This data reflects - Low precision and low accuracy Low precision and high accuracy Low accuracy and high precision High accuracy and high precision

62 2007.1. What is the volume of the liquid in the graduated cylinder?
13.00mL 13.50 mL 14.00mL 14.50mL

63 2007. 12. A sample of iron has a volume of 10. 0 mL
A sample of iron has a volume of 10.0 mL. the density of iron is 7.87 g/mL. Which is the correct expression to calculate the mass of the sample using dimensional analysis? F G H J

64 Student 1 Student 2 Student 3 Student 4
Four students each took three temperature readings of a sample of water. The actual temperature of the sample was 80.0°C. Which student’s measurements were both accurate and precise? Student 1 Student 2 Student 3 Student 4

65 Which of these is the proper method for using a thermometer to measure the temperature of liquid in a beaker? F G H J

66 2007. 30. Sulfuric acid (H2SO4) is spilled on a laboratory bench
Sulfuric acid (H2SO4) is spilled on a laboratory bench. Which chemical would be useful for neutralizing the acid? Aluminum chloride (AlCl3) Potassium nitrate (KNO3) Silver iodide (AgI) Sodium bicarbonate (NaHCO3)

67 2007.37. Which is the safest practice when heating the contents of a test tube over a flame?
Wearing long hair down. Having safety goggles within reach Pointing the test tube away from people Keeping the test tube securely stoppered

68 2007. 41. The boiling point of ethanol is 78. 3°C
The boiling point of ethanol is 78.3°C. The boiling point of ethanol on the Kelvin scale is approximately-- 26K 178K 351K 451K

69 2007.45. The proper scientific notation for 565,000,000,000 is---
.565 x 1012 5.65 x 1011 56.5 x 1010 565 x 109

70 Which of these is the percent of error in evaluating the molecular mass of a compound if the experimental value was amu and the known value was amu? 1.0% 2.1% 3.3% 4.2%

71 A student performed a series of titrations to find the concentration of an unknown acid. The results of the titrations are shown in the data table. What is the mean of this set of data? 0.971 M 0.976 M 0.984 M 1.00 M

72 2008.11. Which set of equipment would be most useful to determine the density of a liquid?
Balance and periodic table Periodic table and thermometer Balance and graduated cylinder Graduated cylinder and thermometer

73 2008. 13. The picture shows a filtration process
The picture shows a filtration process. Which of these is least likely to pass into the test tube? Dissolved gasses Dissolved salts Liquid solvents Solid particles

74 After 1911, most scientists accepted the theory that the nucleus of an atom was very dense and very small and had a positive charge. What led scientists to accept this theory? Dalton’s theory of the atom was over 100 years old. Scientists before 1911 used the scientific method of inquiry improperly. A new model proved that the quantum theory of the atom was inaccurate. Rutherford did an experiment firing alpha particles at a thin piece of gold foil.

75 2008. 23. A student is given a container of potassium nitrate crystals
A student is given a container of potassium nitrate crystals. In order to determine the exact mass of the potassium nitrate using a triple beam balance, he must know the - Mass of the filled container and the chemical formula for potassium nitrate Mass of the filled container and the density of potassium nitrate Volume of the filled container and the volume of the potassium nitrate Mass of the empty container and the mass of the filled container

76 Molar mass Melting point Vapor pressure Temperature
The following results of a scientific study on water were found in a chemistry handbook. What is the independent variable in the study? Molar mass Melting point Vapor pressure Temperature

77 pH probe Motion sensor Pressure sensor Temperature probe
To determine if a reaction is exothermic, a student should use a - pH probe Motion sensor Pressure sensor Temperature probe

78 A student hypothesizes that the solubility of a particular solute in water is nearly constant as temperature varies. The student can best test the hypothesis by doing which of the following? Researching the chemical properties of many different solutes Measuring the solubility of the solute at five different temperatures Drawing diagrams of the molecular structures of water and of the solute Measuring the solubility of several different solutes at a fixed temperature

79 Inversely proportional to pressure Directly proportional to pressure
The table shows the measurements of the volume and the pressure of a portion of a gas at constant temperature. After graphing, the data reveals that the volume is — Inversely proportional to pressure Directly proportional to pressure Inversely proportional to pressure squared Directly proportional to pressure squared

80 Picture Choice 1 Picture Choice 2 Picture Choice 3 Picture Choice 4 1.
The accepted value for the specific heat of aluminum is Which of the following sets of specific heat values for aluminum, calculated from a prior experiment, has the greatest accuracy and precision? 1. Picture Choice 1 Picture Choice 2 Picture Choice 3 Picture Choice 4 2. 3. 4.

81 2009. 1. Which of these would be best to measure 12
Which of these would be best to measure mL of liquid ethanol? 25 mL beaker 25 mL volumetric flask 25 mL Erlenmeyer flask 25 mL graduated cylinder

82 2009. 4. A compound has a mass of 2. 6632 x 102 g/mol
A compound has a mass of x 102 g/mol. The number of significant figures in this mass is -- 2 4 5 7

83 4.39 mL 4.41 mL 4.55 mL 5.61 mL

84 2009.14. If a sample has a mass of 1.25 X 102 g and a volume of 51 mL, what is its density?
g/mL g/mL 2.5 g/mL 250 g/mL

85 2009.30. Letting the chemical evaporate by blowing fans on the spill
Diluting the chemical with water, absorbing the liquid with inert material, and disposing of it in the trash Wiping up the chemical using paper towels and disposing of them in the trash Absorbing the chemical with inert material and disposing of it in a chemical waste container

86 2009.34. Which is the best use for a fume hood?
Storing glassware Removing toxic vapors Covering volatile compounds Mixing chemicals that release O2

87 Chromatography Decanting Filtration Evaporation
Students want to separate and compare the components of black ink and green ink. Which technique is the best for the students to use. Chromatography Decanting Filtration Evaporation

88 Picture Choice 1 Picture Choice 2 Picture Choice 3 Picture Choice 4
Picture Choice 1 Picture Choice 2 Picture Choice 3 Picture Choice 4 1. 2. 3. 4.

89 Which of these best describes the basis on which new scientific ideas are accepted or rejected? Popular support Historical support Compelling evidence Moral and ethical beliefs

90 A student determined that the density of a sample of tin is 8.00 g/mL, when the actual density of tin is 7.28 g/mL. What was the percent error in the student’s calculation? 0.72% 9.0% 9.9% 91%


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