teks end-of-course assessment chemistry practice test...

TEKS

STAAR Chemistry Practice Test A

Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

End-of-Course AssessmentChemistry Practice Test A

1 A student performs the following tests to determine the identity of a mineral sample from its physical and chemical properties.

Test 1 Microscopic examination of the mineral to see the shape of its crystals

Test 2 Scratch test of the mineral to determine its hardness

Test 3 Rubbing the mineral on a streak plate to determine the color of its powdered form

Test 4 Dropping dilute hydrochloric acid on the mineral to see if bubbles will form

Which of the tests would involve a chemical change in the mineral?

A Tests 2 and 4

B Tests 3 and 4

C Tests 1, 2, and 4

D Test 4 only

2 A chemistry student makes careful observations and measurements of a small sample of matter, and determines the following:

Appearance silver solid

Mass 11.85 g

Density 5.9 g/cm3

Melting point 30ºC

The student determines that the unknown substance is gallium (Ga). Which of the following is an extensive property of the gallium sample?

A Silver solid

B Mass of 11.85 g

C Density of 5.9 g/cm3

D Melting point of 30°C

215

STR12_ANC_CHEM_EM_PTA.indd 215 2/7/12 11:04 AM



3 The braking systems in modern cars are designed with components utilizing the compressibility properties of solids, liquids, and gases. The compressibility properties of solids, liquids, and gases are —

A different for all three states of matter

B the same for solids and gases but not for liquids

C the same for gases and liquids but not for solids

D the same for solids and liquids but not for gases

4 Students in a laboratory are asked to test whether a given sample of liquid matter is a pure substance or a mixture. At their stations, two lab partners make the statements in the following table.

Student 1 If we evaporate some of the sample and a residue remains, that means it is a mixture.

Student 2 Whether the sample is a pure substance or a mixture of two volatile substances, no residue will remain if we evaporate it.

Which of the following is correct?

A Statement 1 is true and statement 2 is false.

B Statement 1 is false and statement 2 is true.

C Both statements 1 and 2 are true.

D Both statements 1 and 2 are false.

216




5 The graph below shows a periodic trend.

50

0 10 20 30

Atomic number40 50 60

100

150

200

250

300

Sc

Zn

Cd

Perio

d 1

Period 2Period 3

Period 4 Period 5

HeNe

KrXe

Ar

Li

Na

KRb

Cs

From the trends shown, which of the variables below is plotted on the vertical axis of the graph?

A Ionic radius

B Atomic radius

C Electronegativity

D First ionization energy

6 Compared to other periodic tables in his time, the table developed by Dmitri Mendeleev —

A enabled him to predict chemical and physical properties of yet undiscovered elements

B arranged elements in order of increasing atomic number

C was the only one that arranged elements into groups with similar chemical and physical properties

D had all elements arranged in perfect order of increasing atomic mass

217




7 The table below gives information about a certain element found in the Periodic Table.

Element exists as diatomic molecules

High reactivity Usually gains one electron to form compounds

Rarely found as a free element

The element is most likely a member of which chemical family?

A Alkali metals

B Alkaline earth metals

C Halogens

D Transition metals

8 The following two equations represent changes to water.

1. H2O(l ) → H2O(s) + Energy

2. H2O(l ) + Energy → 2H2(g) + O2(g)

A physical change is represented by —

A both 1 and 2

B neither 1 nor 2

C 2 only

D 1 only

9 A transparent liquid has uniform color. Under a microscope, no difference in uniformity is apparent. The liquid passes unchanged through a filter paper. Based on this information it may be concluded that the liquid is —

A an element

B either a pure substance or a homogeneous mixture

C either an element or a heterogeneous mixture

D a heterogeneous mixture

218




10 Which of the properties listed in the table below are not usually identified with transition metals?

1. Conduct an electric current

2. Shiny

3. Liquid at room temperature

4. Form several common oxidation states

5. Highly reactive

A 4 and 5

B 2 and 4

C 3 and 5

D 1 and 3

11 Some of the Group 1A elements are listed alphabetically in the table below?

1. Cesium

2. Lithium

3. Potassium

4. Rubidium

5. Sodium

Arrange the elements in order of increasing electronegativity. List the numbers of the elements from the table above, with the number of the element with lowest electronegativity on the left and the highest electronegativity on the right.

Record your answer and fill in the bubbles on your answer document.

219




12 A liquid has slightly different properties than a solid because in a solid the particles —

A are free to flow past one another

B are close together

C get bigger when the temperature increases

D vibrate in place

13 The figure below illustrates the electromagnetic spectrum.

Frequency � (s−1)

Wavelength � (m)

Radio waves Radar Microwaves Infrared Ultraviolet X-rays Gamma rays

Visible light

102 10–2 10–4 10–6 10–8 10–10 10–12 10–141

3 × 106 3 × 108 3 × 1010 3 × 1012 3 × 1018 3 × 1020 3 × 1022

Red light, low energy (7.0 × 10–7 m =

700 nm)

Violet light, high energy (3.8 × 10–7 m =

380 nm)

3 × 1014 3 × 1016

Using the figure above, determine which of the following choices records types of electromagnetic waves in order of increasing energy?

A Infrared, ultraviolet, gamma, visible

B Ultraviolet, visible, microwave, radio

C Visible, microwave, x-ray, gamma

D Radar, infrared, visible, ultraviolet, x-ray

220

STR12_ANC_CHEM_EM_PTA.indd 220 2/13/12 1:26 PM



14 Cell phones operate with a range of frequencies between 500 MHz and 4 GHz. Which of the following could be the wavelength of a cell phone electromagnetic wave?

A 1000 km

B 5 m

C 50 cm

D 1 cm

15 Ernest Rutherford devised an experiment in 1911 to probe the structure of the atom.

Observations and Possible Conclusions from the Rutherford Gold Foil Experiment

1. The reflected alpha particles bounced off of the positively charged nucleus — which proved the existence of the nucleus.

2. The reflected alpha particles bounced off of the atoms in the gold foil — which proved the existence of atoms.

3. Most of the alpha particles went straight through the gold foil undeflected — which proved that atoms are neutral.

4. Most of the alpha particles went straight through the gold foil undeflected — which proved that the positive charge was spread out evenly through the atom.

Which of these conclusions did Rutherford draw?

A 1

B 2

C 3

D 4

221




16 Uranium has several naturally occurring isotopes.

Isotope Relative Abundance Mass (amu)

U-238 99.3% 238.05

U-235 0.7% 235.04

What is the average atomic mass of uranium to the nearest hundredth of an atomic mass unit?


17 The electron configuration of phosphorus is [Ne] 3s23p3. Which of the following shows the correct electron dot structure of phosphorus?

A P

B Ne

C P

D Ne

18 The element bromine (Br) has 35 electrons. Those electrons are arranged in many different energy levels. Which of the following lists all of the energy levels that would contain electrons for ground state bromine?

A 1s, 2s, 2p, 3s, 3p, 4s, 4p

B 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p

C 1s, 1p, 2s, 2p, 3s, 3p, 4s, 3d, 4p

D 1s, 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d

222




19 Which equation correctly shows the beta decay of cesium-137?

A 13755 Cs → 0

–1 e + 13756 Ba

B 13755 Cs → 0

–1 e + 13754 Xe

C 13755 Cs → 0

0 γ + 13755 Cs

D 13755 Cs → 4

2 Hw + 13353 I

20 Radon gas, Rn-222, is produced during alpha decay according to the reaction represented by the following equation.

X → 22246 Rn + 4

2 He

What element decays to produce radon gas?

A Ra-226

B Po-218

C Fr-223

D Th-226

21 A student investigates several different forms of nuclear radiation and makes the following list of characteristics of one type.

Characteristics of a Type of Nuclear Radiation

No mass

Has a negative charge

Can be blocked by a sheet of aluminum foil

Which type of particle was investigated?

A Alpha

B Beta

C Positron

D Gamma

223




22 A student finds a bottle of HNO3 stored with other highly toxic and corrosive materials. In ancient times, this chemical was called aqua fortis, or “strong water,” because it was used in alchemy to dissolve silver and other metals. What is the IUPAC name of the compound?

A Hydrogen nitric oxide

B Hydrogen nitrate

C Nitrous acid

D Nitric acid

23 P2O5 is a very strong desiccator and is used in organic synthesis to dehydrate molecules. What is the name of the compound?

A phosphorus pentoxide

B phosphorus oxide

C diphosphorus tetroxide

D diphosphorus pentoxide

24 Aluminum sulfate is used in water purification and wastewater treatment to take colloids out of suspension. It is also found in baking powder and in antiperspirants. What is the chemical formula for aluminum sulfate?

A AlS2O4

B AlSO4

C Al(SO4)3

D Al2(SO4)3

224




25 A student is searching for a bottle containing iron(III) hydroxide. Which formula will be written on the label of the bottle?

A Fe3(OH)2

B FeH3O

C Fe3OH

D Fe(OH)3

26 Gallium sulfide (Ga2S3) is a yellow solid with a distinct rotten egg odor that ignites spontaneously in air. Which of the following is the correct electron dot formula?

A S Ga S Ga S C S 3−

S 3−

S 3−

Ga2+

Ga2+

B S 2−

S 2−

S 2−

Ga3+

Ga3+

D

Ga

S

S

S

Ga

225




27 Formaldehyde (CH2O) is a toxic compound used to preserve organic tissue. Which of the following is the correct electron dot structure for the molecule?

A C

O

HH

B H C O H

C C H H O

D

C

H

H

O

28 A boron atom has 3 valence electrons. What is the structure of a molecule of boron trichloride (BCl3) according to VSEPR theory?

A Pyramidal

B Trigonal planar

C Tetrahedral

D Linear

29 Which of the following corresponds with one mole of particles?

A 6.02 × 1023 grams of CO2 × 1 mol CO2

44 grams = 1.37 × 1022 mol CO2

B 6.02 × 1023 molecules of CO2

3 atoms / molecule = 2.00 × 1023 atoms CO2

C 6.02 × 1023 molecules of CO2

D 6.02 × 1023 molecules of CO2 × 3 atoms

1 molecule CO2

= 18.06 × 1023 atoms CO2

226




30 How many molecules are in 45.0 g of C6H6?

A 1.04 × 1024 molecules

B 3.47 × 1023 molecules

C 2.71 × 1025 molecules

D 1.34 × 1022 molecules

31 How many ions are present in 50.0 grams of hydrogen cyanide (HCN)?

A 3.34 × 1024 ions

B 6.50 × 1023 ions

C 1.11 × 1024 ions

D 2.23 × 1024 ions

32 A compound contains 62.0% carbon, 10.4% hydrogen, and 27.5% oxygen. What is the empirical formula for the compound?

A C2H4O

B CH3O

C C3H6O

D CH2O

227




33 Which coefficient belongs before H2SO4 when the equation shown is balanced?

H2SO4 + Fe → Fe2(SO4)3 + H2

A 1

B 2

C 3

D 4

34 Ethane (C2H6) is a colorless gas used as a fuel. Ethane burns in oxygen to produce carbon dioxide and water. The balanced chemical equation that describes this reaction is —

A 2C2H6 + 7O2 → 4CO2 + 6H2O

B 2C2H6 + 5O2 → 3CO2 + 6H2O

C C2H6 + 7O2 → 4CO2 + 3H2O

D 3C2H6 + 7O2 → 6CO2 + 9H2O

35 In an experiment, 19.2 g of water is produced when 10.0 g of methane is burned in an excess of oxygen. What is the percentage yield of water, to the nearest tenth of a percent?

CH4(g) + 2O2 → CO2(g) + 2H2O(g)


228




36 With a deep breath, human lungs will contain about 5.00 L of air. If the pressure is 1.00 atm, and the temperature of the air in your lungs is 35.0°C, how many millimoles of oxygen will be in the lungs, if the air is 20.95% oxygen?

A 198 mmol

B 365 mmol

C 1.74 × 103 mmol

D 41.4 mmol

37 There are two balloons of identical size: one filled with air and the other with helium. Assume that the pressure and temperature in each balloon is the same. Which balloon weighs more and what is the ratio of the masses? Assume that air is 80% nitrogen and 20% oxygen.

A The air balloon weighs about 7 times more than the helium balloon.

B The air balloon weighs about 4 times more than the helium balloon.

C The balloons have exactly the same mass of gas.

D The helium balloon weighs about 3 times more than the air balloon.

38 The partial pressures of the various gases in our atmosphere can be explained by the kinetic molecular theory. Which of the statements below are correct postulates of the kinetic molecular theory?

1. Gas particles move in random, rapid, straight line motion between collisions.

2. Gases are mostly empty space containing very tiny hard spheres which repeatedly collide.

3. The absolute temperature of the gas is a measure of the total kinetic energy of the particles.

4. In any collision between gas particles, none of the total kinetic energy of the particles is lost.

A 1 and 2

B 2 and 4

C 1, 2, and 4

D 1, 3, and 4

229




39 Many electric cars and hybrid electric vehicles use a regenerative braking system that converts the kinetic energy of the car to chemical energy of the battery. When brakes are applied, the electric motors become electrical generators, recharging chemical energy of the battery as they slow down the vehicle.

Power out

Power in

Electric motor Electric motor

Right Front Wheel

AccelerationPower in from battery; motor turns wheel

BrakingWheel turns motor; power returned to batteries

Comparing the chemical energy input from the battery, which accelerates the vehicle, to the chemical energy returned to the battery when the vehicle slowly brakes to a stop, we would expect the returned energy to be —

A equal to the energy input because of the law of conservation of energy

B more than the energy input because the tires and generators will heat up

C less than the energy input because electrical energy generation is an endothermic process

D less than the energy input because some heat will inevitably be lost to the surroundings

230




40 In the catalytic converter of a car, one of the chemical reactions that occur converts poisonous carbon monoxide to less toxic carbon dioxide. Using average bond energies from the table below, estimate the chemical potential energy change of the reaction described by this equation:

2CO(g) + O2(g) → 2CO2(g)

(Note: The carbon-oxygen bond in carbon monoxide is actually a resonance hybrid bond. But for the purposes of this question, assume it is a simple double bond.)

Bond O = O O – H C = O C – O O – O

Average Bond Energy (kJ/mol) 498 467 745 358 204

A –992 kJ/mol

B +992 kJ/mol

C –498 kJ/mol

D +498 kJ/mol

41 The reaction shown in the graph below could be represented by which of the following equations?

Energy

Reaction Coordinate

Reactants

Products

A Reactants + heat → Products (as an exothermic reaction)

B Reactants → Products + heat (as an exothermic reaction)

C Reactants + heat → Products (as an endothermic reaction)

D Reactants → Products + heat (as an endothermic reaction)

231




42 On a warm day, a large glass of water is placed in a refrigerator. Calculate the specific heat of the glass using the recorded measurements in the table below, given that the refrigerator removes 39.4 kJ from the glass and water.

Substance Glass Water

Mass (g) 322 320

Initial temperature (ºC) 28.4 28.4

Final temperature (ºC) 3.9 3.9

Specific heat capacity (J/g·ºC) ? 4.18

A 0.840 J/g∙°C

B 4.15 J/g∙°C

C 0.154 J/g∙°C

D 0.819 J/g∙°C

43 A student is given a constant-pressure calorimeter as shown below and asked to determine the molar heat of solution of potassium nitrate, KNO3(s). The student records the data shown in the table.

Mass of beaker 106.8 g

Mass of beaker and KNO3(s) 144.6 g

Volume of water 200 mL

Initial temperature of water 22.3ºC

Final temperature of water 6.7ºC

Density of water 1.00 g/mL

Heat capacity of water 4.18 J/g·ºC

Using the recorded measurements, calculate the molar heat of solution of potassium nitrate to the nearest tenth of a kJ/mol.

Record your answer and fill in the bubbles on your answer document. Be sure to indicate whether the value is positive or negative.

ThermometerStirrer

Nested foam cups

Water

Foam lid

Constant-PressureCalorimeter

Mass of beakerMass of beaker and KNO3(s)Volume of waterInitial temperature of waterFinal temperature of waterDensity of waterHeat capacity of water

106.8 g144.6 g200 mL22.3ºC6.7ºC1.00 g/mL4.18 J/g·ºC

232




44 Which of the following reactions is an acid-base reaction?

A 4Al(s) + 3O2(g) → 2Al2O3(s)

B Ca(NO3)2(aq) + Na2SO4(aq) → CaSO4(s) + 2NaNO3(aq)

C HClO4(aq) + KOH(aq) → KClO4(aq) + H2O(l)

D KBr(aq) + AgNO3(aq) → KNO3(aq) + AgBr(s)

45 Use the table below to predict which of the following would be expected if dilute solutions of Na2SO4(aq) and Ba(NO3)2(aq) are mixed.

Salts of alkali metals and ammonia

Nitrate salts and chlorate salts

Sulfate salts

Chloride salts

Carbonates, phosphates, chromates, sulfides, and hydroxides

Solubility Rules for Ionic Compounds in Aqueous Solutions

Compounds Solubility Exceptions

Soluble

Soluble

Soluble

Soluble

Most are insoluble

Some lithium compounds

Few exceptions

Compounds of Pb, Ag, Hg, Ba, Sr, and Ca

Compounds of Ag and some compounds of Hg and Pb

Compounds of the alkali metals and of ammonia

A No precipitate would be observed.

B Both NaNO3(s) and BaSO4(s) would precipitate.

C BaSO4(s) would precipitate.

D NaNO3(s) would precipitate.

233




46 A laboratory assistant follows written directions and prepares a solution for an experiment that contains 30.0 g of Na2SO4 in 400 mL of solution. What is the molar concentration of that solution to three decimal places?


47 Aqueous solutions of Ag2SO4 and an unknown compound are mixed and two different precipitates form. An equation representing the situation is

Ag2SO4(aq) + (aq) → Ag (s) + SO4(s)

Which of the following could be the unknown compound?

A PbCO3

B SrCl2

C PbCl2

D Na2CO3

48 A student is asked to determine whether a given solution is an electrolyte. Which of the following pieces of laboratory equipment would be the most useful for that purpose?

A pH meter

B Conductivity apparatus

C Burette and chemical indicator

D High grade filter paper and funnel

234




49 a b When a tiny crystal of the solute is dropped into a solution, a b the crystal appears to grow rapidly and other crystals appear in the solution.

These observations indicate that the solution was —

A concentrated

B unsaturated

C saturated

D supersaturated

50 Based on the graph below, an increase in temperature —

A usually affects the solubility of ionic compounds

B increases the solubility of ionic compounds

C causes compounds to dissolve

D increases the rate at which substances dissolve

a b

140

160

120

100

80

60

40

0

20

10 20 30 40 50 60 70 80 90Temperature (ºC)

KNO3

NH4Cl

NaCl

NaNO3

Solu

bilit

y (g

/100

g H

2O)

KBr

Yb2(SO4)3

Solubility Varies With Temperature

235




51 Based on the graph below, the solubility of oxygen in water increases with —

Temperature (ºC)

Oxy

gen

Solu

bilit

y (m

g/L)

Pressure (atm)

60

50

40

30

20

10

01050 15 302520 35 40 45 50

Oxygen Solubility in Fresh Water

421

A an increase in both pressure and temperature

B a decrease in both pressure and temperature

C a decrease in pressure and an increase in temperature

D an increase in pressure and a decrease in temperature

52 In an oxidation-reduction reaction, which of the following are transferred?

A Protons and electrons

B Electrons and neutrons

C Electrons only

D Protons only

236



STAAR Chemistry Practice Test A Answer Sheet

Answer Sheet

Name Date Class

1.2.3.4.5.6.7.8.9.

10.

11.

12.13.14.15.16.

17.18.19.20.21.22.23.

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

A B C D

A B C D

A B C D

A B C D

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

24.25.26.27.28.29.30.31.32.33.34.35.

36.37.38.39.40.41.42.43.

44.45.

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

A B C D

A B C D

237



STAAR Chemistry Practice Test A Answer Sheet

Answer Sheet

Name Date Class

46. A B C D

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

47.48.49.50.51.52.

A B C D

A B C D

A B C D

A B C D

A B C D

A B C D

238


teks end-of-course assessment chemistry practice test...

Documents