Chem Final Exam Review

The experimentally determined rate law for the reaction (CH3)3CBr + OH− → (CH3)3COH + Br− is rate = k [(CH3)3CBr]. A postulated mechanism is (CH3)3CBr → (CH3)3C + + Br− (1) (CH3)3C + + OH− → (CH3)3COH (2) Which reaction represents the rate determing step? 1. More information is needed. 2. (CH3)3CBr → (CH3)3C + + Br− 3. (CH3)3C + + OH− → (CH3)3COH

. 2. (CH3)3CBr → (CH3)3C + + Br−

Methanol (CH3OH) and ethanol (C2H5OH) are common organic solvents. The vapor pressures of pure methanol and pure ethanol at 25◦C are 122.7 torr and 58.9 torr, respectively. If the mole fraction of CH3OH in the mixture of the two solvents at 25◦C is 0.4, what is the mole fraction of C2H5OH in the vapor phase that is in equilibrium with the liquid mixture? 0.234 .895 .419 .567 .80 .208 .534

.419

While sipping a refreshing glass of ice water, which of the following thoughts about the drink is incorrect? 1. pH = pOH = 7 2. pH > 7 3. pH = pOH 4. pOH > 7

1. pH = pOH = 7

Consider the following reaction and its rate constant. A → B k = 0.103 min−1 What will be the concentration of A after 564 seconds if the reaction started with a concentration of 0.400 M ? 1. 0.115 M 2. 0.308 M 3. 0.361 M 4. 0.0843 M 5. 0.384 M 6. 0.288 M 7. 0.152 M 8. 0.236 M

0.152

The system H2(g) + I2(g) ⇀↽ 2 HI(g) is at equilibrium at a fixed temperature with a partial pressure of H2 of 0.200 atm, a partial pressure of I2 of 0.200 atm, and a partial pressure of HI of 0.100 atm. An additional 0.35 atm pressure of HI is admitted to the container, and it is allowed to come to equilibrium again. What is the new partial pressure of HI? 1. 0.148 2. 0.17 3. 0.154 4. 0.132 5. 0.164 6. 0.136 7. 0.14 8. 0.168 9. 0.156 10. 0.138

0.17

What is the vapor pressure of carbon disulfide at its normal boiling point?

1 atm

Write the autoprotolysis reaction for liquid ammonia. 1. NH3(ℓ) ⇀↽ NH− 2 (solvated) + H+(solvated) 2. NH− 2 (aq) + NH3(ℓ) ⇀↽ NH+ 4 (solvated) + NH2−(solvated) 3. 2 NH3(ℓ) ⇀↽ NH− 2 (solvated) + NH+ 4 (solvated) 4. NH3(ℓ) + H2O(ℓ) ⇀↽ NH− 2 + H3O +(aq) 5. NH3(ℓ) + NH+ 4 (aq) ⇀↽ NH+ 4 (aq) + NH3(ℓ) 6. NH3(ℓ) + H2O(ℓ) ⇀↽ NH+ 4 (aq) + OH−(aq)

3. 2 NH3(ℓ) ⇀↽ NH− 2 (solvated) + NH+ 4 (solvated)

A reaction A → products is observed to obey second-order kinetics. Which of the following choices would give a straight line plot where the slope equals the rate constant? 1. 1 [A] vs t2. [A] vs t 3. [A] vs 1 k 4. 1 [A] vs 1 t 5. ln[A] vs k 6. [A] vs √ t 7. ln[A] vs 1 k

1. 1 [A] vs t

Determine the pH of a 2.4×10−2 M solution of Sr(OH) 1. 12.6812 2. 12.5315 3. 12.6232 4. 12.7324 5. 12.6021 6. 12.699 7. 12.415 8. 12.301 9. 12.9445 10. 12.8062

1. 12.6812

For H2O, Kf =1.86 C/m The freezing point of an aqueous sodium chloride solution is −29 ◦C. What is the molality of the solution? 6.7789 2.1456 31.65 7.7957 4.67 2.0

1. 7.7957 correct

Rank the species CH3OH, CH3F, HF, C3H4 from most to least miscible in propane (C3H8): 1. C3H4 > CH3F > CH3OH > HF 2. C3H4 > CH3OH > HF > CH3F 3. CH3OH > HF > C3H4 > CH3F 4. CH3F > C3H4 > CH3OH > HF 5. CH3F > CH3F > HF > CH3OH

1. C3H4 > CH3F > CH3OH > HF

Rank these compound by vapor pressure from lowest to highest 1. C3H7OH < CH3OH < C3H8 < CH4 2. C3H8 < CH4 < C3H7OH < CH3OH 3. C3H7OH < C3H8 < CH3OH < CH4 4. CH4 < C3H8 < CH3OH < C3H7OH 5. CH4 < CH3OH < C3H8 < C3H7OH 6. CH3OH < C3H7OH < CH4 < C3H8

1. C3H7OH < CH3OH < C3H8 < CH4

For the cell diagram Pt| H2(g), H +(aq)|| Cu2+(aq)| Cu(s), which reaction occurs at the anode? 1. H2(g) → 2 H+(aq) + 2 e − 2. 2 H+(aq) + 2 e − → H2(g) 3. Cu(s) → Cu2+(aq) + 2 e − 4. Cu2+(aq) + 2 e − → Cu(s) 5. 2 H+(aq) + Cu(s) → H2(g) + Cu2+(aq)

1. H2(g) → 2 H+(aq) + 2 e

Listed in order of increasing acid strength, which pair is incorrect? 1. HClO4 < HClO2 2. HNO2 < HNO3 3. H3AsO4 < H3PO4 4. H2SO3 < H2SO4 5. H2Se < H2Te

1. HClO4 < HClO2

Two clear liquids are spilled on the floor. One of the liquids evaporates faster than the other. This evidence implies that... 1. The IMFs are weaker and, thus, the vapor pressure is higher in the liquid that evaporated faster. 2. The IMFs are stronger and, thus, the vapor pressure is higher in the liquid that evaporated faster. 3. The IMFs are stronger and, thus, the vapor pressure is lower in the liquid that evaporated faster. 4. The IMFs are weaker and, thus, the vapor pressure is lower in the liquid that evaporated faster.

1. The IMFs are weaker and, thus, the vapor pressure is higher in the liquid that evaporated faster.

As we increase the temperature of a liquid, its properties change. Which of the following would NOT be an expected change in the properties of a typical liquid as we increase its temperature? 1. increase in surface tension 2. decrease in viscosity 3. increase in vapor pressure 4. increase in tendency to evaporate 5. decrease in density

1. increase in surface tension

Consider isobutanol and n-butanol. They have the same chemical formula, and thus the same molecular weight. However, isobutanol is a branched molecule while n-butanol is linear. Which of the following is true about the boiling points of isobutanol and n-butanol? 1. isobutanol will have a lower boiling point than n-butanol 2. Their boiling point will be the same. 3. n-butanol will have a lower boiling point than isobutanol

1. isobutanol will have a lower boiling point than n-butanol

NOTE: DO NOT FORGET TO WRITE A CHEMICAL EQUATION FOR THE REACTION THAT TAKES PLACE. A 130 mL portion of 0.4 M acetic acid is being titrated with 0.4 M NaOH solution. What is the pH of the solution after 120 mL of the NaOH solution has been added? The ionization constant of acetic acid is 1.8 × 10−5 . 1. pH = 5.82 2. pH = 4.77 3. pH = 6.04 4. pH = 4.32 5. pH = 6.55

1. pH = 5.82

Suppose the reaction mixture H2(g) + Cl2(g) ⇀↽ 2 HCl(g) is at equilibrium at a given temperature and pressure. The pressure is then increased at constant temperature by compressing the reaction mixture, and the mixture is then allowed to reestablish equilibrium. At the new equilibrium 1. there is the same amount of hydrogen chloride as there was originally. 2. there is less hydrogen present than there was originally. 3. the hydrogen and chlorine are completely used up. 4. the amount of hydrogen chloride present may either be greater or smaller than it was originally, depending on the value of K. 5. there is more hydroge

1. there is the same amount of hydrogen chloride as there was originally.

The relationship between the solubility s in water and Ksp for the ionic solid M2A3 is 1. Ksp = 5 s. 2. Ksp = s 5 . 3. Ksp = 108 s 5 4. Ksp = 6 s 2 .

108 s 5 . correct

WATCH YOUR UNITS AND DRAW A HEATING CURVE!! The molar heat capacity of C6H6(ℓ) is 136 J/mol · ◦C and of C6H6(g) is 81.6 J/mol · ◦C.The molar heat of fusion for benzene is 9.92 kJ/mol and its molar heat of vaporization is 30.8 kJ/mol. The melting point of benzene is 5.5◦C, its boiling point is 80.1◦C, and its molecular weight 78.0 g/mol. How much heat would be required to convert 234 g of solid benzene (C6H6(s)) at 5.5◦C into benzene vapor (C6H6(g)) at 100.0◦C? 200 157.468 501.356 2357.9 145.768 200.56

157.468 kJ

If octane has a pure vapor pressure of 20 torr at 30 ◦C and cyclopentane has a pure vapor pressure of 400 torr at 30 ◦C, a mixture of 6 moles of octane and 4 moles of cyclopentane would have what total vapor pressure? 300 torr 207 torr 124 torr 172 torr 165 torr 179 torr

172 torr

Manganese (Mn) exhibits a larger number of oxidation numbers in its compounds than any other Period 4 transition metal. The most important oxidation numbers of manganese are illustrated by the oxides MnO, MnO2, and Mn2O7. What oxidation numbers of manganese are illustrated here?

2. +2; +4, and +7

NOTE: Write the half reaction. How many moles of of metallic iron (Fe) could be produced from Fe2+ at a current of 0.004 amperes for 964,853 seconds? 1. 0.4 mol Fe 2. 0.02 mol Fe 3. 0.04 mol Fe 4. 0.2 mol Fe

2. 0.02 mol Fe

When 20.0 grams of an unknown compound are dissolved in 500 grams of benzene, the freezing point of the resulting solution is 3.77◦C. The freezing point of pure benzene is 5.48◦C, and its freezing point depression constant is Kf = 5.12◦C/molality. What is the molecular weight of the unknown compound? 1. 160 grams/mole 2. 120 grams/mole 3. 140 grams/mole 4. 100 grams/mole 5. 80.0 grams/mole

2. 120 grams/mole

What is the pH of a 0.30 M solution of anilinium nitrate (C6H5NH3NO3)? Kb for aniline (C6H5NH2) is 4.2 × 10−10 . 1. 2.4 2. 2.6 3. 9.1 4. 2.7 5. 4.9 6. 2.3

2. 2.6

HCl = 36.45 g/mol and NaCl = 58.45 g/mol. Calculate the resulting pH obtained by mixing 16.5 g HCl and 22.6 g NaCl in water to create 482 L solution. 1. 1.13 2. 3.03 3. 3.92 4. 4.31 5. 2.15 6. 5.67

2. 3.03

Consider the voltaic cell Pt | Sn4+ (0.0010 M), Sn2+ (0.10 M) || Ag+ (0.010 M) | Ag Sn4+ + 2 e − → Sn2+ E 0 = 0.15 V Ag+ + 1 e − → Ag(s) E 0 = 0.8 V Under these conditions, the cell potential is 1. 0.62 V. 2. 0.68 V. 3. 0.72 V. 4. 0.65 V. 5. 0.59 V

5. 0.59 V.

NOTE: THE REACTION IS REVERSIBLE. The reaction for the synthesis of ammonia N2(g) + 3 H2(g) → 2 NH3(g) is exothermic. Increasing the temperature applied to the system I) increases the amount of NH3. II) decreases the amount of NH3. III) changes the value of Keq. IV) does not change the value of Keq. 1. I and IV only IV) does not change the value of Keq. 1. I and IV only 2. II and III only 3. II and IV only 4. I and III only3. II and IV only 4. I and III only

2. II and III only correct

A reaction is at equilibrium. You add a catalyst. This causes the reaction to 1. shift to the right.. 2. No shift would occur due to the catalyst.3. The direction of the shift would depend on ∆H. 4. shift to the left.

2. No shift would occur due to the catalyst.

What is true when a liquid is at its equilibrium vapor pressure? 1. The system is at the critical point. 2. The rates of condensation and evaporation are the same 3. The system is neither evaporating nor condensing. 4. The rate of condensation exceeds that of evaporation. 5. The rate of evaporation exceeds that of condensation.

2. The rates of condensation and evaporation are the same.

The phase diagram for a pure substance is given below. What pressure must be applied to liquefy a sample at 425 K?

2. The sample cannot be liquefied at 425 K. correct (because it is past the critical point on diagram)

Maintaining electrolyte balance in the body is essential for regular cell function. Based on what you know about osmotic pressure, which of the following is most likely to occur if the ion concentration outside of a cell suddenly becomes much higher than the ion concentration on the inside of the cell? 1. Water will flow into the cell, causing the cell to swell. 2. Water will flow out of the cell, causing the cell to shrink. 3. Nothing. The flow of water is not dependent on ion concentrations. 4. Water will flow out of the cell, causing the cell to swell. 5. Water will flow into the cell, causing the cell to shrink

2. Water will flow out of the cell, causing the cell to shrink.

For the reaction Al3+ + 3 NH3 → [Al(NH3)3] 3+ Al3+ is best described as 1. neither an acid nor a base. 2. a Lewis acid. 3. a Lewis base. 4. a Brønsted acid. 5. a Brønsted base.

2. a Lewis acid.

A water solution of NaI will exhibit a pH value of 1. less than 7. 2. about 7. 3. zero. 4. greater than 7.

2. about 7

NOTE: NO CALCULATIONS NEEDED! THINK AND SAVE TIME. Which combination of ∆G◦ and K is possible at standard conditions? 1. ∆G ◦ = −45.2 J, K = 1.2 × 10−17 2. ∆G ◦ = −107 J, K = 1.04 3. ∆G ◦ = 97.4 kJ, K = 1.02 4. ∆G ◦ = −65.2 kJ, K = 0.965 5. ∆G ◦ = 90.3 J, K = 2.12 × 1011

2. ∆G ◦ = −107 J, K = 1.04

Given the reversible reaction equation 2 CO(g) + O2(g) ⇀↽ 2 CO2(g) which is the relationship between Kc and Kp? 1. Kp = Kc 2. Kp = Kc (R T) −2 3. Kp = Kc (R T) −1 4. Kp = Kc (R T) 2 5. Kp = Kc R T

3 Kp = Kc (R T) −1

A solution of 0.90 g of an unknown nonelectrolyte in 300 mL of water at 27◦C has an osmotic pressure of 38.4 torr. What is the molecular weight of this compound? Hint: Neglect volume change due to solute. R = 0.08206 L · atm mol · K 1. 5.81 × 104 g/mol 2. 4.72 × 105 g/mol 3. 1.52 × 103 g/mol 4. 3.78 × 102 g/mol 5. 1.46 × 103 g/mol

5. 1.46 × 10 3 g/mol

Which one of the following statements is false?Carbon tetrachloride (CCl4) is more soluble with hexane (C6H14) than it is with a polar solvent such as methanol (CH3OH). 2. As temperature increases, the solubilities of some solids in liquids increase and the solubilities of other solids in liquids decrease. arrow_right_alt 3. Gases are generally more soluble in water at high temperatures than at low temperatures. 4. Gases are generally more soluble in water under high pressures than under low pressures. 5. Water dissolves many ionic solutes because of its ability to hydrate ions in solution.

3. Gases are generally more soluble in water at high temperatures than at low temperatures.

Write the equilibrium expression for the reaction 2 Fe(s) + 3 2 O2(g) ←→ Fe2O3(s)

3. K = 1 / P O2 ^3/2

Which of the following gases are more soluble in water when their partial pressure above the solution is increased? HI, SO3, NH3, O2, NO2, HF, Cl2 1. Cl2, NO2, SO3, HI 2. HI, NH3 3. all of them 4. NO2, O2, HI 5. SO3, NO2, HI 6. NO2, SO3

3. all of them

The introduction of a catalyst into a reaction mixture at equilibium would 1. change the relative amounts of reactants and products present at equilibrium. 2. change ∆G 0 for the reaction. 3. change the activation energy Ea of the reaction. 4. change the value of the equilibrium constant. 5. change ∆Hrxn.

3. change the activation energy Ea of the reaction.

NOTE: The bicarbonate ion is HCO3-. In the reaction CO2− 3 + H2O → HCO− 3 + OH− what is the role of the bicarbonate ion? 1. base 2. acid 3. conjugate acid 4. conjugate base

3. conjugate acid

molar solubility

3. the number of moles that dissolve to give one liter of saturated solution

What would be pH of a 0.0002 M solution of hypochlorous acid if hypochlorous acid has a Ka = 5 × 10−5 ? 1. 7 2. 14 3. 4 4. 8 5. 10

4

The equilibrium constant for the reaction H2(g) + I2(g) ⇀↽ 2 HI(g) has the value K = 54 at 700◦C. Find the value of K for the reaction 4 HI(g) ⇀↽ 2 H2(g) + 2 I2(g) at the same temperature. 1. 0.14 2. 0.019 3. 2900 4. 0.00034 5. 7.3

4. 0.00034

A diprotic acid H2A has values of Ka1 = 1.0 × 10−6 and Ka2 = 1.0 × 10−10. What is the [A2−] in a 0.10 M solution of H2A? 1. 3.2 × 10−4 M 2. 3.2 × 10−6 M 3. 0.20 M 4. 1.0 × 10−10 M 5. 0.10 M

4. 1.0 × 10−10 M

A solution whose pH is 3 is how many times as acidic as a solution whose pH is 6? 1. 100 2. 6 3. 2 4. 1000 5. 10

4. 1000

NOTE: DO NOT FORGET TO WRITE A CHEMICAL EQUATION FOR THE REACTION THAT TAKES PLACE. What is the final pH of a solution containing 100 mL of 0.5 M HNO2 and 100 mL of 0.1 M NaNO2 after 0.03 mol of NaOH are added? The pKa is 3.37. 1. 3.37 2. 1.02 3. 10.33 4. 3.67 5. 3.03

4. 3.67

NOTE: DO NOT FORGET TO WRITE A CHEMICAL EQUATION FOR THE REACTION THAT TAKES PLACE. A 100 mL sample of 0.100 M NH3 solution is titrated to the equivalence point with 50 mL of 0.200 M HCl. What is the final [H3O +]? The ionization constant of NH3 is 1.8 × 10−5 . 1. 1.00 × 10−7 M 2. 1.10 × 10−3 M 3. 8.61 × 10−6 M 4. 6.09 × 10−6 M 5. 3.70 × 10−11 M

4. 6.09 × 10−6 M

In which of the following cases will the LEAST time be required to arrive at equilibrium? K below refers to the equilibrium constant 1. Cannot tell without knowing the value of K. 2. K is a very large number. 3. K is about 1. 4. Cannot tell since the time to arrive at equilibrium does not depend on K. 5. K is a very small number.

4. Cannot tell since the time to arrive at equilibrium does not depend on K.

Which of the following is the strongest oxidizing agent? 1. Cl2 2. Cr2O 2− 7 3. MnO− 4 4. H2O2

4. H2O2

Consider the polyprotic acid H3AsO4 (arsenic acid), which has Ka values, in no particular order, of 10−7 , 10−2 , and 10−12 for the equilibria shown below: Ka1: H3AsO4 ⇀↽ H2AsO4 − + H+ Ka2: H2AsO4 − ⇀↽ HAsO4 2− + H+ Ka3: HAsO4 2− ⇀↽ AsO4 3− + H+ Correctly identify the values of Ka2 and Ka3 1. Ka2 = 10−7 , Ka3 = 10−2 2. Ka2 = 10−12 , Ka3 = 10−7 3. Ka2 = 10−2 , Ka3 = 10−12 4. Ka2 = 10−7 , Ka3 = 10−12 5. Ka2 = 10−2 , Ka3 = 10−7 6. Ka2 = 10−12 , Ka3 = 10−2

4. Ka2 = 10−7 , Ka3 = 10−12 correct

Which response is FALSE? An acid/base indicator 1. might exist in an acidic form. 2. might exist in a basic form. 3. might have one highly colored form and one colorless form. 4. has a color-change range that is independent of its own ionization constant value. 5. might have two highly colored forms

4. has a color-change range that is independent of its own ionization constant value.

Consider the mechanisn NO2(g) + F2(g) → NO2F(g) + F(g) slow F(g) + NO2(g) → NO2F(g) fast What does the reaction profile show? 1. two maxima, the second being highest 2. one maximum for the second step 3. two maxima, both the same height 4. two maxima, the first being highest

4. two maxima, the first being highest

a reaction has k+8.39 m-1s-1. how long does it take for the reactant concentration to drop from .0840M to .0220 M?

4.00 s

Balance the redox reaction Fe2+(aq) + MnO− 4 (aq) → Fe3+(aq) + Mn2+(aq) that occurs in an acidic solution. What is the coefficient of Fe2+?

5

The un-ionized form of an acid indicator is yellow and its anion is blue. The Ka of this indicator is 10−6 . What will be the approximate pH range over which this indicator changes color? 1. 8 → 10 2. 9 → 11 3. 4 → 6 4. 3 → 5 5. 5 → 7 c

5. 5 → 7

What additional information, if any, would enable you to calculate the molality of a 7.35 molar solution of a nonelectrolyte solid dissolved in water? 1. Only the molecular weight of the solute would be needed. 2. None is needed. 3. Only the density of the solution would be needed. 4. Only the density of water would be needed. 5. Both the density of the solution and the molecular weight of the solute would be needed.

5. Both the density of the solution and the molecular weight of the solute would be needed.

Each of the following samples was placed in 1 liter of water. I) 0.6 mol NaOH II) 0.7 mol KCl III) 0.5 mol Na2CO3 IV) 1 mol of sugar Rank the solutions that are made in terms of increasing order of boiling point elevation. (Remember your solubility rules.) 1. IV, II, I, III 2. II, IV, I, III 3. III, I, IV, II 4. III, I, II, IV 5. IV, I, II, III

5. IV, I, II, III

What are the oxidation numbers of the elements in the compound Na3PO3? 1. Na = +1, P = +2, O = −2 2. Na = −1, P = −3, O = +2 3. Na = +3, P = +3, O = −2 4. Na = +2, P = −3, O = −1 5. Na = +1, P = +3, O = −2

5. Na = +1, P = +3, O = −2

graph- which statement is true

5. The position of equilibrium will change if the temperature is changed.

Which statement is FALSE? 1. The reaction rate for a zero-order reaction is independent of concentrations. 2. The rate law expression relates rate and concentration. 3. The integrated rate equation relates time and concentration. 4. The half-life for a second-order reaction decreases with increasing initial concentrations. 5. The rate constant for a reaction is independent of temperature.

5. The rate constant for a reaction is independent of temperature.

A typical fresh egg white will have a pH of 7.80. This corresponds to 1. [H3O +] of 8.0 × 10−7 M; [OH−] of 1.3 × 10−8 M . 2. [H3O +] of 8.5 × 10−7 M; [OH−] of 5.5 × 10−7 M . 3. [H3O +] of 3.0 × 10−8 M; [OH−] of 3.3 × 10−7 M . 4. [H3O +] of 7.0 × 10−8 M; [OH−] of 1.4 ×10−7 M . 5. [H3O +] of 1.6 × 10−8 M; [OH−] of 6.3 × 10−7 M

5. [H3O +] of 1.6 × 10−8 M; [OH−] of 6.3 × 10−7 M

Which of the following is NOT a weak acid? 1. acetic acid 2. sulfurous acid 3. hydrofluoric acid 4. phosphoric acid 5. chloric acid 6. cyanic acid 7. carbonic acid 8. hypochlorous aci

5. chloric acid

When a moderate amount of acid is added to a buffer, the pH should 1. decrease greatly. 2. stay the same. 3. increase slightly. 4. increase greatly. 5. decrease slightly.

5. decrease slightly.

Which species will reduce Ag+ but not Fe2+? 1. Cr 2. V 3. Pt 4. Au 5. H2

5. h2

A buffer solution containing ethanoic acid and sodium ethanoate is resistant to large change in pH when a strong base is added because 1. the stated effect would not occur; this solution is buffered only against the addition of a strong acid. 2. some of the ethanoate ion hydrolyzes producing hydronium ions, which partly neutralize the added base. 3. some of the added hydroxide ions react with hydronium ions from the acid and more ethanoic acid is then formed from the ethanoate ions present. 4. the ethanoate ion reacts with part of the hydroxide ions so that the effect on the pH is small. 5. some of the ethanoic acid ionizes to produce hydronium ions, which partly neutralize the added hydroxide ions.

5. some of the ethanoic acid ionizes to produce hydronium ions, which partly neutralize the added hydroxide ions.

For H2O (l), Cs = 4.18J/g.C For H2O(s) Cs = 2.09 J/g.C Enthalpy of fusion of ice = 334 J/g . Consider an insulated system containing 419 g of water at 25◦C. Adding 173 g of ice at −10◦C will result in equilibrium conditions at 0.0◦C with how many grams of ice remaining? 45.8 57.9 409.1 52.6 67.0 57.9

52.6

Ka for HF = 7.2x10−4 How many grams of NaF (of MW 42.0) would have to be added to 2.00 L of 0.100 M HF to yield a solution with a pH = 4.00? 1. 6.9 g 2. 36 g 3. 60 g 4. 0.84 g 5. 300 g

60 g

What is the pH when 100 mL of 0.1 M HCl is titrated with 50 mL of 0.2 M NaOH?

7 ph

Under certain conditions, the reaction 3 A + 4 B → 5 C is observed to proceed at a rate of 0.0338 M · s −1 . What is the corresponding rate of change in product C? 1. 0.0112667 M · s −1 2. −0.0338 M · s −1 3. 0.00676 M · s −1 4. 0.1014 M · s −1 5. −0.169 M · s −1 6. −0.1014 M · s −1 7. 0.169 M · s −1 8. −0.0112667 M · s −1 9. 0.0338 M · s −1 10. −0.00676 M · s −1

7. 0.169 M · s −1

What is the pH of a solution in which the concentration of hypochlorous acid (HClO) is 0.70 M and the concentration of sodium hypochlorite (NaClO) is 1.2 M? (Ka for HClO = 3.2 × 10−8 ) 1. 9.1 2. 7.3 3. 5.3 4. 4.7 5. 6.6 6. 6.1 7. 8.3 8. 7.7

8. 7.7

What is the pH of a solution made by dissolving 0.100 mole of sodium acetate (NaCH3COO) in enough water to make one liter of solution? Ka for CH3COOH is 1.80 × 10−5 . 1. 5.56 × 10−10 2. 5.13 3. 9.25 4. 7.46 × 10−6 5. 10.25 6. 3.75 7. 1.82 × 10−6 8. 5.56 × 10−11 9. 8.87 10. 1.80 × 10−6

9. 8.87

AgCl would be least soluble in 1. pure water. 2. 0.1 M CaCl2. 3. 0.1 M HNO3. 4. 0.1 M NH3. 5. 0.1 M HCl.

CaCl2

Assume you add 10 mL of water in an evacuated and sealed container held at 25 ◦C. Which of the following would decrease the vapor pressure? I) adding a nonvolatile solute II) halving the size of the container III) removing some liquid

I only

Consider what you have learned about the reactivity of acids and bases. Another definition of acids and bases focuses on the tendencies of these molecules to accept and donate a share in a pair of electrons, respectively. Which of the statements I) Acids are electron pair donors; II) Bases are electron pair acceptors; III) Acids are electron pair acceptors; IV) Bases are electron pair donors

III) Acids are electron pair acceptors; IV) Bases are electron pair donors.

Which of the following gases are soluble in water due to their chemical reactivity?HI,SO3,NH3,O2,NO2,HF,Cl2

NO2, SO3

Which of the following is a soluble base? 1. ammonia 2. zinc hydroxide 3. magnesium hydroxide 4. aluminum hydroxide 5. copper(II) hydroxide 6. iron(III) hydroxi

ammonia

Adding NH4BrO to pure water would result in what kind of solution? Ka for HBrO is 2.5 × 10−9 and Kb for NH3 is 1.8 × 10−5 . 1. basic 2. neutral 3. acidic

basic

graph

k is greater than 1

Four of the following are colligative properties of solutions. Which one is not a colligative property? 1. vapor pressure lowering 2. molality 3. freezing point depression 4. boiling point elevation 5. osmotic pressure

molality

NOTE: THE REACTION IS REVERSIBLE. The equilibrium constant for the reaction HNO2(aq) + H2O(ℓ) → NO− 2 (aq) + H3O +(aq) is 4.3 × 10−4 at 25◦ C. Will nitrous acid spontaneously dissociate when [HNO2(aq)] = 0.15 M and [NO− 2 (aq)] = [H3O +(aq)] = 1.0 × 10−2 M?

no

what takes place at the negatively charged terminal of a voltaic cell

oxidation

Hydroxylamine is a weak molecular base with Kb = 6.6 × 10−9 . What is the pH of a 0.0500 M solution of hydroxylamine? 1. pH = 3.63 2. pH = 10.37 3. pH = 7.12 4. pH = 8.93 5. pH = 9.26 6. pH = 4.74 7. pH = 9.48

pH = 9.26

buffer

resists ph change

3 vapor pressure graphs

very easy just read graph