Quiz 2 Flashcards

1
Q

NH4Cl is a

A

Salt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which one of these compounds is insoluble in water?

A- BaSO4

B- NaCL

C- KI

D- HCl

E- No correct answer is given

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Identify a Strong Base

A- HNO3

B- KCl

C- NH4OH

D- NaOH

E-Na2SO4

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Hydrogen gas reacts with oxygen gas to form water vapor. If 34.5 g of hydrogen gas react with 26.6 g of oxygen gas, how many grams of water vapor will be produced? (Hint: two reactants, two quantities => limiting reactant problem).

2H2(g) + O2(g) -> 2H2O(g)

A

30.0 g H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Hydrogen gas reacts with excess nitrogen gas to form ammonia gas (NH3). If 10.2 g of hydrogen gas react with excess of nitrogen gas, how many grams of ammonia gas will be produced? (Hint: one reactant is excess!).

A

57.4 g NH3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Acid-base reaction is a neutralization reaction. If 12.50 mL of 1.20 M NaOH solution is used to neutralize 45.25 mL of HNO3 solution, calculate the concentration of the original HNO3 solution.

A

0.331 M

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Acid-base reaction is a neutralization reaction. If 12.50 mL of 1.20 M NaOH solution is used to neutralize 45.25 mL of H2SO4 solution, calculate the concentration of the original H2SO4 solution.

NaOH + H2SO4 -> 2H2O (not balanced)

A

0.166 M

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

(T/F)

Oxidation-reduction (redox) reactions involve electrons. If an element in ground state loses two electros during the redox reaction, this process si called oxidation.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the oxidation number of P in H3PO4?

A

P= +5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the oxidation number of P in PO43-?

A

P= +5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which of the following molecule is an electrolyte?

A- Pure Water

B- Sugar Solution

C- Pure butanol

D- KCl solution

E- More than one answer is given

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The reaction of 22.5 of Fe with excess of oxygen gas produced 24.2 g of Fe2O3. Calculate the percent yeld. (hint: one reactant, O2, is excess, so the Fe is the limiting reactant)

A

75.2%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Milk of magnesia contains magnesium hydroxide. What mass of Mg(OH)2 is needed to prepare 500.00 mL of 0.0500 M solution of magnesium hydroxide?

A

1.46 g of Mg(OH)2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What element is oxidized in the following reaction?

2Li + O2 -> Li2O

A- Li

B- O2

C- more than one correct answer is given

D- no correct answer is given

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Identify/ predict the products of the reaction between Na2SO4 and BaCl2 solutions. (SOLUBILITY RULES)

A

NaCl + BaSO4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Write the complete molecular equation for the reaction between Na2SO4 and BaCl2 solutions.

A

2NaCl(aq) + BaSO4(s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Write the complete ionic equation for the reaction between Na2SO4 and BaCl2 solutions

A

2Na+(aq) + SO42-(aq) + Ba2+(aq) + 2Cl-(aq) -> 2 Na+(aq) + 2Cl-(aq) + BaSO4(s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Write the net ionic equation for the reaction between Na2SO4 and BaCl2 Solutions

A

SO42-(aq) + Ba2+(aq) -> BaSO4(s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Identify the driving force(s) in the reaction between Na2SO4 and BaCl2

A

Formation fo a precipitate (ppt) BaSO4(s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How many moles in 24.02 fo CO2?

A

0.5458 mol CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How many grams in 8.79 moles of CH4?

A

141 g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In the following reaction, how many grams of sodium sulfate are needed to react with 3.08 moles of strontium nitrate? (hint: stoichimoetry Na2SO4: Sr(NO3)2 = 1:1)

Sr(NO3)2 + Na2SO4 -> SrSO4 + 2 NaNO3 (balanced)

A

437 g Na2SO4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

If 10.89 g of silver are recovered when 42.88 g of zinc and 29.50 g of silver nitrate are reacted, calculate the precent yield? (hint: limiting reactant problem; the euqation is balanced for you.)

Zn + 2AgNO3 -> An(NO3)2 + 2Ag (balanced)

A

58.14%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Strong electrolytes are…

A- Always Salts

B- always acids

C- always bases

D- always ionic compounds

E- no correct answer given

A

E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which is of the followign is the net ionic equation for

Pb(NO3)2 + 2NaI -> 2NaNO3 + PbI2 (Balanced?)

A-Pb(NO3)2 +2NaI -> 2 NaNO3 +PbI2

B- Pb2+ + 2 I- -> PbI2

C-Pb2+ + 2 I- -> 2PbI2

D- NO3- + Na+ -> NaNO3

E- No correct answer given

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the driving force in the reaction

HCl + NaOH -> NaCl + H2O

A

Formation of a nonelectrolyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

(T/F)

PbI2 cannot be used as an electrolyte

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

(T/F)

At room temperature a sample that has a weak intermolecular attractions is most likely to be a gas.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What volume is occupied by 0.550 moles of as at 1.00 atm and 313 K?

A

V= 14.1 L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What volume will 0.245 moles of gas occupy at 98.2°F and 755 mmHg?

A

V= 6.28 L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the pressure of a sample of gas after it is compressed from 2.00 L, 2.00 atm to 0.250 L at a constant temperature?

A

Pressure= 16.0 atm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the temperature of a sample of gas after it is allowed to expand from 1.50 L, 6.00 atm and 293 K to 5.60 L and 0.180 atm?

A

Temperature = 33.0 K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the temperature of 10.45 moles of a gas in a 4.00 L cylinder at 2.50 atm?

A

Temperature- 11.7 K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

A 4.50 L gas cylinder contains 1.50 g of O2 and 4.30 g of N2. What is the pressure in the cylinder at 22.00°C?

A

Pressure= 1.08 atm

35
Q

How many grams of Cl2 are in a 25.0 L cylinder at 250.0 torr and 293 K?

A

24.2 g Cl2

36
Q

(T/F)

At STP, the pressure is 1.00 atm and the temperature is 273°C

A

False

37
Q

Which of these statements is true about gases?

A- Gas molecules are in constant motion except at 0 K

B- gas molecules interact very well

C- Gases exert little pressure

D- Gas molecules are large compared to the distances between them

E- Temperature does not affect the rate of motion of gas molecules

A

A

38
Q

A pressure of 475. mm Hg has what value measured in atmospheres?

A

0.625 atm

39
Q

Inflate a 2.50 liter ballon in a place where the atmospheric pressure is 715. torr. What will the volume of the ballon be in a place where the atmospheric pressure is 760. torr?

A

Volume = 2.35 L

40
Q

(T/F)

Kinetic energy is the energy of motion and change

A

true

41
Q

If a sample of 0.50 moles of He occupies 4.2 L under certain conditions, what volume will 0.23 moles occupy under the same conditions?

A

volume = 1.9 L

42
Q

What is the volume of 2.75 g of H2 gas at 4.75 atm and 315 K?

A

Volume = 7.43 L

43
Q

A 0.465 g sample of an unkown compound occupies 0.245 L at 298 K and 17.9 psi. What is the molar mass of the unknown compound?

A

38.06 g/mol

44
Q

A mixture of 5.00 g of He and 5.00 g of Ne have a total pressure of 2.50 atm. What is the partial pressure of He?

A

2.08 atm

45
Q

Calculate the root mean square velocity of hydrogen molecules at 22.00°C.

Urms= (3RT/M)1/2

R= 8.314 J/mol. K

A

Urms= 1911 m/s

46
Q

One of the following equation/law is used to calculate the properties of a gas under non-ideal conditions.

A- Dalton’s law

B- Charle’s Law

C- Boyle’s Law

D- van der Waals equation

E- Avagodro’s law

A

D

47
Q

The atmospheric pressure is 720. mmHg. What is the pressure in inches of Hg (inHg)?

A

28.3 inHg

48
Q

Which of the following samples has the greatest density at STP?

A- SF6

B- NO

C- He

D- CO2

E- All of these marterials have the same density at STP

A

A

49
Q

A mixture of 0.152 moles of NO, 0.245 moles of H2 and 0.993 moles of Ar has a total pressure of 5.75 atm. Calculate the partial pressure of Ar

A

4.11 atm

50
Q

Calcium hydride (CaH2) reacts with water to form hydrogen gas, according to the following reaction.

CaH2(S) + 2H2O(l) -> Ca(OH)2(aq) + 2H2(g)

How many grams of calcium hydride (CaH2) are needed to generate 2.50 L of hydrogen gas at a pressure of 0.900 atm and a temperature of 38.20°C?

A

1.85 g CaH2

51
Q

Consider the following combustion reaction:

C2H4(g) + O2(g) -> CO2(g) +H2O(g) (not balanced)

determine the number of liters of CO2 gas formed at STP when 2.45 grams of C2H4(g) is burned with excess oxygen.

A

3.91 L

52
Q

(T/F)

A non-electrolyte is a substance, when dissolved in water, can conduct electricity.

A

False

53
Q

What might happen when calcium nitrate [Ca(NO3)2] solution is mixed with a potassium phophate (K3PO4) solution.

A

formation of an insoluble solid, Ca3(PO4)2(s)

54
Q

How many grams of potassium dichromate (K2Cr2O7) are required to prepare a 500.00 mL solution with a concentration of 1.50 M? (MM of K2Cr2O7 is 294.2 g/mol)

A

221 g

55
Q

In a titration experiment a student found that 25.55 mL of 1.00 M KOH solution are required to neutralize 37.75 ml of sulfuric acid (H2SO4) What is the concentration of H2SO4 solution (Hint: write the balanced equation)

A

0.338 M

56
Q

Which of the following gas will have the greatest volume at STP?

A- 2.5 g N2

B- 2.5 g O2

C- 2.5 g Ar

D- 2.5 g NO

E- 2.5 g CO2

A

A

57
Q

The volume of a gas is proporational to number of moles of gas at constant pressure and constant temperature is known as….

A

Avogadro’s law

58
Q

How many grams of KCl(s) are produced from the decomposition of KClO3(s) which produces 125.0 L fo O2(g) at 34.5°C and 1.22 atm pressure?

A

0.300 g KCl

59
Q

How much energy is needed to warm 25.0 g of benzene from 1.00°C to 8.00°C? (Csp of benzene can be found in the CRC handbook fo chemistry and physics- Library website)

A

265 J

60
Q

The production of 1.00 g of C2H2 gas from graphite and H2 gas requires 8.7033 kJ under standard conditions. What is the (delta)H°f(C2H2)?

2 C(graphite) + H2(g) -> C2H2(g)

A

226.6 kJ/mol

61
Q

How much energy will warm 10.0 g of gold if the (delta)T= 4.1°C?

A

5.25 J

62
Q

How many joules need to be added to 4.50 g of graphite to raise its temperature by 25 K? (Csp of graphite can be found in teh CRC handbook of chemistry and physics- library website)

A

81 J

63
Q

What is the heat of reaction for the reaction

2Fe(s) + O3 (g) -> Fe2O3

A

-966.9 kJ/mol

64
Q

What is the specific heat of a material if 45.0 J are needed to warm a 2.25 g sample of 0.0°C to 22.0°C?

A

0.909 J/g°C

65
Q

(T/F)

thermal energy is a form of chemical energy

A

False

66
Q

(T/F)

An open system is one that can gain (or lose) matter and energy

A

True

67
Q

How much heat (in kJ) is transferred from surroundings to warm 100.0g of water from 5.0°C to 22.0°C?

A

7.11 kJ

68
Q

A 5.5 g block of Cu at 95.0°C is placed in 100.0 ml of water at 22.5°C. What is the final temperature of the water. (Hint- this problem involves transfer of heat energy.) (D= 1.00 g/mL)

A

22.9°C

69
Q

what is (delta)H°reaction for 2SO2(s) + O2 -> 2 SO3(g)

(delta) H°f SO3= -395.7 kJ/mol
(delta) H°f SO2 = -296.8 kJ/mol
(delta) H°f O2(g) = O kJ/mol

A

-197.8 kJ/mol

70
Q

Which one is true based on the following reaction?

CH4(g) + 2O2(g) -> CO2(g) + 2H2O(g)

(delta)H°rxn = -802.3 kJ

A- this is an endothermic reaction

B- this is an exothermic reaction

C- the products have more potential energy

D- the reactants have more potential energy

E- more than one correct answer is given

A

E

B/D are correct

71
Q

(T/F)

in exothermic reactions, the products of the reaction have more potential energy than the reactants

A

False

72
Q

Which of the following signs on q and w represent a system that is doing work on the surroundings, as well as gaining heat from the surroundings?

A- q= +, w= -

B- q= -, w=+

C- q=+, W=+

D- q= -, w= -

E- non of these represent the system referenced above

A

A

73
Q

Use the (delta)H°f and (delta)H°rxn information provided to calculate (delta)H°f for HCl(g)

CH4(g) + 4Cl2(g) -> CCl4(g) + 4HCl(g)

(delta) H°rxn = -389 kJ
(delta) H°f of CH4(g) = -75 kJ/mol
(delta) H°f of CCl4(g) = -96 kJ/mol

A

-92 kJ/mol

74
Q

Calculate the change internal energy (deltaE) for a system that is giving off 45.0 kJ of heat and is performing 895 J of work on the surroundings

A

-45.9 kJ

75
Q

(T/F)

Heat capacity: The quantity of heat required to change a system’s temperature by 1°C

A

True

76
Q

(T/F)

Specific heat capacity: The quantity of heat required to raise the temperature of 1 gram of a substance by 1°C (Hint: consider analyzing the units of Cs)

A

True

77
Q

A 4.00 g sample of water at 22.5°C is heated by the addition of 98.0 J of energy. The final temperature of the water is ___°C (the specific heat capacity of water is 4.18 J/g°C)

A

28.4°C

78
Q

When 0.500 g of cyclohexane (C6H12) is combusted in a bomb calorimeter that has a water sheath containing 750.0 g of water, the temperature of the water increased by 5.5°C. Assuming that the specific heat of water is 4.18 J/g°C, and that the heat absorption by the calorimeter is negligible, calculate the enthalpy of combustion per mole of cyclohexane.

A

2.90 * 106 J/mol

79
Q

Choose the reaction that illustrates (delta)H°f for Ca(NO3)2

A- Ca(s) + N2(g) + 3O2(g) -> Ca(NO3)2(s)

B- Ca+(aq) + NO3-(aq) -> Ca(NO3)2(s)

C-Ca+(aq) + NO3(aq) -> Ca(NO3)2(s)

D- Ca(s) + N2(g) + O2(g) -> Ca(NO3)2(s)

E- 2Ca(s) + 2N2(g) +3O2(g) -> Ca(NO3)2(s)

A

A

80
Q

Identify a green-house gas

A- O3(g)

B- C2H4(g)

C- CO2(g)

D- H2O(g)

E- More than one correct answer is given

A

E

A, C, D are all correct

81
Q

(T/F)

The temperature of pressure for the standard state for a liquid are 298 K and 1 atm

A

true

82
Q

Give teh equation with the elements Na2SO4 in their standard state as the reactants and Na2SO4 as the product.

A

2Na(s) + 1/8S8(s, rhombic) +2O2(g) -> Na2SO4

83
Q
A