Sample Questions Flashcards

1
Q

How many moles of HCl are required to react with 13.0 grams of zinc?
Zn + 2HCl -> ZnCl2 + H2 (Zn = 65.38; H = 1.01; Cl = 35.45)

A

0.400 mole

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2
Q

How many liters (L) of 15 M HCl are required to react with 33.0 grams of zinc?
Zn + 2HCl -> ZnCl2 + H2 (Zn = 65.38; H = 1.01; Cl = 35.45)

A

0.0673 L

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3
Q

How many grams of NaOH would be required to react with 2.50L of 4.75M sulfuric acid? H2SO4 + 2NaOH -> Na2SO4 + H2O

A
  1. g
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4
Q

Ammonia and phosphoric acid solutions are used to produce ammonium hydrogen phosphate fertilizer. What volume of 42.6 M NH3(aq) is needed to react with 1000. L of 14.8 M of H3PO4(aq)?
2NH3(aq) + H3PO4(aq) -> (NH4)2HPO4(aq)

A

695 L

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5
Q

What volume (in L) of 0.500 M sodium chloride will produce with 325 mL of 0.250 M barium sulfate to completely precipitate all Ba^2+ in the solution?
Na2SO4(aq) + BaCl2(aq) -> BaSO4 (s) + 2 NaCL (s)

A

0.325 L

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6
Q

When a direct electric current flows through an electrolytic cell, a chemical reaction occurs. Which process is demonstrated in the statement?

A

Electrolysis

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7
Q

Strong electrolytes are substances that are completely ionized when they are dissolved in water. They conduct electrical currents very efficiently. Which of the following is a strong electrolyte?

A

Hydrochloric acid

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8
Q

What is the freezing point of a 10.0% (by weight) solution of CH3OH in water. Assume that there is 1.00 kg solution. (Kf = 1.86) (MM = CH3OH = 32.05)

A

-6.45 C

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9
Q

When 20.6g of a nonvolatile substance is dissolved in 855g of ether, its boiling point is raised 0.324C. What is the molecular weight of the substance? Molal boiling point constant for ether is Kb = 2.11

A

157 g/mol

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10
Q

A solution of 100.8g of non-dissociating solute in 135.0g of water has a freezing point of -5.16C. What is the molar mass of the solute? FPofWater = 0C & Kf(water) = 1.86

A

269 g/mol

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11
Q

At 37.0C, the osmotic pressure of a blood sample was 7.60 atm. The average person’s blood volume is 5.00 L. one liter of blood contains 8.70 grams of solute. What is the molar mass?

A

5.82 g/mol

(29.1 g/mol sa ans key)

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12
Q

John Patrick Isidro, a grade 12 STEM student is conducting a laboratory experiment. He reacted a solution of known concentration to a solution of unknown concentration. Which of the following laboratory procedures is MOST appropriate to determine the molarity of the solution?

A

Titration

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13
Q

Joshua Patrick Bandola is given a laboratory task to make a new solution (dilute) from a stock solution (concentrated). What will be the correct procedure to attain his task?

A

C-A-B-D

Calculate, Measure, Add Solvent, Stir

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14
Q

Which of the following statement below is/are FALSE?

A

III only

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15
Q

Which of the following terms describes a reaction in which there is a net transfer of energy from a system to its surroundings - that is, where more energy is released by bond formation that is consumed by bond cleavage?

A

Exothermic

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16
Q

Which BEST describes the molecules in a solid?

A

They are attracted to each other so strongly that the molecules cannot slide past each other.

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17
Q

Which statement is TRUE about liquids based on the kinetic molecular theory?

A

The force of attraction between its molecules is moderate.

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18
Q

Which of the following phrases/words BEST complete the statement below?

Diploe-dipole forces are weaker than ________ and stronger than ________ interactions.

A

ion-ion, london

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19
Q

What type of intermolecular forces of attraction are present with hydrobromic acid?

A

dipole-dipole

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20
Q

Which of the following includes compounds that exhibit hydrogen bonding?

A

CH3NH2, HF, HI

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21
Q

Refer to the phase diagram of carbon dioxide. At what pressure does carbon dioxide sublime directly into vapor?

A

1 atm

22
Q

Triple point occurs when three phases of a substance co-exist. At what temperature and pressure would show the triple point of water?

A

at 0.01 C and 0.006 atm

23
Q

Which of the following properties is generally exhibited by amorphous solids?

A

Amorphous solids turn into a brittle glass-like state from a flexible rubber-like state upon cooling.

24
Q

Which of the following statements is NOT true about crystalline solids?

A

Crystalline solids do not possess any rigidity.

25
Q

Water cannot dissolve all substances that are made from ionic bonds. This is probably because of ___________.

A

Some ionic bonds are too strong for the attractions of water molecules to pull them apart.

26
Q

Which of the following statements describes the enthalpy change of a reaction?

A

The difference between the energy released by bond formation and energy consumed by bond cleavage during a chemical reaction.

27
Q

What is likely to happen when entropy is increased?

A

I, II, III, and IV

28
Q

The value of ΔHe^o for the reaction below is -88.0 kJ. How many kJ of heat are released when 1.0 mol of HBr is formed in this reaction?

A

44.0 kJ

29
Q

Determine the heat of reaction for the reaction:
4NH3 + 5O2 -> 4NO + 6H2O

A

-906.3 kJ

30
Q

The value of ΔH^o for the reaction below is -238 kJ. How much heat is released by the reaction of 45.0 g of Na2O2 with water?
2Na2O2 + 2H2O -> 4NaOH +O2

A

68.7 kJ

31
Q

Which of the following is TRUE about the rate of reaction?

A

The greater the temperature, the greater the reaction rate

32
Q

Which of the following statements regarding enzymes is FALSE?

A

Enzymes act to lower the activation energy of a reaction by stabilizing the transition state.

33
Q

Which type of intermolecular forces exist between NH3 and HF?

A

Hydrogen bonding

34
Q

Why does water molecule classified as a polar molecule? This is because _____________.

A

oxygen has a stronger attraction for electrons than hydrogen.

35
Q

The rate of removal of alcohol from the bloodstream stays the same, regardless of the concentration of blood alcohol. What term do we use to describe this reaction?

A

zeroth order reaction

36
Q

What happens in the temperature from point D to E?

A

increase

37
Q

How does the temperature of ethanol change during the melting of ethanol?

A

constant

38
Q

A 350. g water solution was collected from a drinking fountain inside a park and found to contain 0.09625 g lead (Pb). What is the concentration of lead in water solution in ppb?

A

275,000 ppb

39
Q

As the polarity in the molecule increases, the melting and boiling points also increase as more heat is needed to break the bonds. Which of the following halogens is arranged based on decreasing boiling point?

A

I2, Br2, Cl2, F2

40
Q

What is the individual order and the order overall for the reaction below?
Reaction: 2A + B -> 2C, Rate equation: Rate = k[A]^2[B]

A

the order with respect to A is 2 and the order overall is 3

41
Q

Oil spreads over the surface of water whereas water does not spread over the surface of the oil, which of the following BEST explains this?

A

Surface tension of water is very high

42
Q

A 55.0 g ethyl alcohol (molar mass = 46.0 g/mol) is dissolved in 145 g water (molar mass = 18.0 g/mol). Calculate the mole fraction of the ethyl alcohol in the solution.

A

0.129

43
Q

Reaction rates generally increase with an increase in temperature. Which of the following statements BEST explain this?

A

I and IV only

44
Q

Which of the following is TRUE about the viscosity of liquids?

A

decreases with increase in temperature

45
Q

When the concentration of reactant molecules is increased, the rate of reaction increases. Which of the following is the BEST explanation for this statement.

A

As the reactant concentration increases, the frequency of molecular collisions increases.

46
Q

How many grams of potassium nitrate would be required to react with 675 mL of 3.27 M nitric acid? (K = 39.1; Br = 79.9; O = 16.0; H = 1.00; N = 14.0)

A

223 g

47
Q

A solution of 100.8 g of a non-dissociating solute in 135.0 g of water has a freezing point of -5.16 C. What is the molar mass of the solute?

A

269 g/mol

48
Q

The second law of thermodynamics tells us that heat cannot flow from __________.

A

cold to hot without external energy

49
Q

Determine the molar mass of a non-dissociating if 20.0 g dissolved in 100.0 mL of solution to give a resulting osmotic pressure of 6.48 atm at 26 C.

A

755 g/mol

50
Q

Which items correctly complete the following statement? A catalyst can act in a chemical reaction to ____________.

A

I and IV only