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CHEM 1211K Test II MULTIPLE CHOICE. (3 points each) 1) The ...

CHEM 1211K Test II MULTIPLE CHOICE. (3 points each) 1) The ...

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<strong>CHEM</strong> <strong>1211K</strong><br />

<strong>Test</strong> <strong>II</strong><br />

<strong>MULTIPLE</strong> <strong>CHOICE</strong>. (3 <strong>points</strong> <strong>each</strong>)<br />

1) <strong>The</strong> charge on the manganese in the salt MnF 3 is __________.<br />

A) +1 B) +2 C) -2 D) +3 E) -1<br />

2) Which formula/name pair is incorrect<br />

A) FeS iron(<strong>II</strong>) sulfide B) FeSO 4 iron(<strong>II</strong>) sulfate<br />

C) FeSO 3 iron(<strong>II</strong>) sulfite D) Fe 2 (SO 3 ) 3 iron(<strong>II</strong>I) sulfite<br />

E) Fe 2 (SO 4 ) 3 iron(<strong>II</strong>I) sulfide<br />

3) <strong>The</strong> name of PCl 3 is __________.<br />

A) monophosphorous trichloride B) phosphorus trichloride<br />

C) trichloro potassium D) phosphorous(<strong>II</strong>I) chloride<br />

E) potassium chloride<br />

4) Which one of the following is the formula of perchloric acid<br />

A) HClO B) HClO 4 C) HClO 3 D) HCl E) HClO 2<br />

5) When the following equation is balanced, the coefficient of water is __________.<br />

N 2 O 5 (g) + H 2 O (l) HNO 3 (aq)<br />

A) 3 B) 2 C) 1 D) 4 E) 5<br />

6) Of the reactions below, which one is a decomposition reaction<br />

A) 2CH 4 + 4O 2 2CO 2 + 4H 2 O B) NH 4 Cl NH 3 + HCl<br />

C) 2N 2 + 3H 2 2NH 3 D) Cd(NO 3 ) 2 + Na 2 S CdS + 2NaNO 3<br />

E) 2Mg + O 2 2MgO<br />

7) <strong>The</strong> formula weight of ammonium sulfate ((NH 4 ) 2 SO 4 is __________ amu.<br />

A) 132 B) 116 C) 118 D) 100 E) 264<br />

8) <strong>The</strong> mass % of Al in aluminum sulfate, Al 2 (SO 4 ) 3 , is __________.<br />

A) 15.77 B) 35.94 C) 45.70 D) 7.886 E) 21.93<br />

9) How many moles of carbon dioxide are there in 52.06 g of carbon dioxide<br />

A) 3.134 x 10 25 B) 0.8452 C) 1.183 D) 8.648 x 10 23 E) 6.022 x 10 23<br />

10) A sulfur oxide is 50.0% by mass sulfur. This molecular formula could be __________.<br />

A) SO 3 B) SO 2 C) SO D) S 2 O E) none of these


11) <strong>The</strong> combustion of propane (C 3 H 8 ) in the presence of excess oxygen yields CO 2 and H 2 O:<br />

C 3 H 8 (g) + 5O 2 (g) 3CO 2 (g) + 4H 2 O (g)<br />

when 2.5 mol of O 2 are consumed in their reaction, __________ mol of CO 2 are produced.<br />

A) 3.0 B) 2.5 C) 5.0 D) 6.0 E) 1.5<br />

12) Pentacarbonyliron (Fe(CO) 5 ) reacts with phosphorous trifluoride (PF 3 ) and hydrogen, releasing carbon<br />

monoxide:<br />

Fe(CO) 5 + 2PF 3 + H 2 Fe(CO) 2 (PF 3 ) 2 (H) 2 + 3CO<br />

<strong>The</strong> reaction of 5.0 mol of Fe(CO) 5 , 8.0 mol of PF 3 and 6.0 mol of H 2 will release __________ mol of CO.<br />

A) 5.0 B) 24 C) 15 D) 12 E) 6.0<br />

13) Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide:<br />

4Al (s) + 3O 2 (g) 2Al 2 O 3 (s)<br />

In a particular experiment, the reaction of 2.5 g of Al with 2.5 g of O 2 produced 3.5 g of Al 2 O 3 . <strong>The</strong> %<br />

yield of the reaction is __________.<br />

A) 37 B) 26 C) 74 D) 47 E) 66<br />

14) <strong>The</strong> net ionic equation for the reaction between aqueous solutions of HCl and KOH is __________.<br />

A) HF + KOH H 2 O + K + + F -<br />

B) HF + OH - H 2 O + F -<br />

C) H + + F - + K + + OH - H 2 O + K + + F -<br />

D) H + + OH - H 2 O<br />

E) HF + K + + OH - H 2 O + KF<br />

15) Which one of the following compounds is insoluble in water<br />

A) FeCl 3 B) ZnS C) K 2 O D) AgNO 3 E) NaCl<br />

16) Which one of the following is a weak acid<br />

A) HClO 4 B) HCl C) HNO 3 D) HI E) HF<br />

17) Oxidation is the __________ and reduction is the __________.<br />

A) loss of oxygen, gain of electrons B) gain of oxygen, loss of electrons<br />

C) loss of electrons, gain of electrons D) gain of electrons, loss of electrons<br />

E) gain of oxygen, loss of mass<br />

18) What is the concentration (M) of CH 3 OH in a solution prepared by dissolving 11.7 g of CH 3 OH in<br />

sufficient water to give 230 mL of solution<br />

A) 1.59 x 10 -3 B) 11.9 C) 0.0841 D) 11.9 x 10 -3 E) 1.59<br />

19) What volume (L) of 0.250 M HNO 3 is required to neutralize a solution prepared by dissolving 17.5 g of<br />

NaOH in 350 mL of water<br />

A) 1.75 B) 50.0 C) 1.75 x 10 -3 D) 0.44 E) 0.070


20) Which one of the following statements is false<br />

A) <strong>The</strong> actual numerical value of E can be measured.<br />

B) ∆E = E final - E initial<br />

C) E is a state function.<br />

D) ∆E = q + w<br />

E) When a system undergoes a process in which it gains energy from the surroundings, the ∆E for the<br />

process is positive.<br />

21) Of the following, which one is a state function<br />

A) q B) w C) heat D) H E) none of the above<br />

22) For a given process at constant pressure, ∆H is negative. This means that the process is _______.<br />

A) a state function B) endothermic C) exothermic D) equithermic E) energy<br />

23) <strong>The</strong> value of ∆H o for the reaction below is -336 kJ. Calculate the heat (kJ) released to the surroundings<br />

when 23.0 g of HCl is formed.<br />

CH 4 (g) + 3Cl 2 (g) CHCl 3 (l) + 3HCl (g)<br />

A) -2.57 x 10 3 B) -70.7 C) -336 D) -211 E) -177<br />

24) <strong>The</strong> enthalpy change for the following reaction is -486.3 kJ:<br />

2H 2 (g) + O 2 (g) 2H 2 O (g)<br />

<strong>The</strong>refore, the enthalpy change for the reaction listed below is ________ kJ:<br />

4H 2 O (g) 4H 2 (g) + 2O 2 (g)<br />

A) -483.6 B) 483.6 C) 967.2 D) -483.6 E) 2.34 x 10 5<br />

25) A chemical reaction that absorbs heat from the surroundings is said to be __________ and has a<br />

__________ ∆H at constant pressure.<br />

A) endothermic, positive B) endothermic, negative<br />

C) exothermic, negative D) exothermic, positive<br />

E) exothermic, neutral


(5 <strong>points</strong>) At one time, a common means of forming small quantities of oxygen gas in a laboratory was to<br />

heat KClO 3 :<br />

2 KClO 3 (s) 2 KCl(s) + 3 O 2 (g) ∆H = -89.4kJ<br />

For this reaction, calculate ∆H for the formation of 3.51mol of O 2<br />

−89.4kJ<br />

x<br />

=<br />

3O<br />

2<br />

3.51mol<br />

x = 104.6kJ<br />

= 105kJ<br />

(10 <strong>points</strong>) Some sulfuric acid is spilled on a lab bench. It can be neutralized by sprinkling sodium bicarbonate<br />

(NaHCO 3 ) on it and then mopping up the resultant solution. <strong>The</strong> sodium bicarbonate reacts with<br />

sulfuric acid as follows:<br />

2 NaHCO 3 (s) + H 2 SO 4 (aq) Na 2 SO 4 (aq) + 2 H 2 O(l) + 2 CO 2 (g)<br />

Sodium bicarbonate is added until the fizzing due to the formation of CO 2 (g) stops. If 27mL of<br />

6.0M H 2 SO 4 was spilled, what is the minimum mass of NaHCO 3 that must be added to the spill to<br />

neutralize the acid<br />

moles H<br />

2<br />

SO<br />

4<br />

= 6.0M<br />

(0.027L<br />

_<br />

= 0.162 mol H<br />

2<br />

SO<br />

4<br />

2 NaHCO<br />

1H<br />

2<br />

SO<br />

4<br />

3<br />

=<br />

x<br />

0.162mol<br />

H<br />

2<br />

x = 0.324 mol<br />

SO<br />

4<br />

NaHCO<br />

3<br />

gNaHCO<br />

3<br />

= 0.324mol<br />

= 27g<br />

( 84.0g<br />

/ mol)


(10 <strong>points</strong>) Lithium and nitrogen react to produce lithium nitride:<br />

6 Li(s) + N 2 (g) 2 Li 3 N(s)<br />

If 5.00g of <strong>each</strong> reactant are allowed to react, how many grams of Li 3 N are formed<br />

5.0g<br />

Moles Li =<br />

6.941g<br />

/ mol<br />

= 0.720mol<br />

Moles N<br />

2<br />

5.0g<br />

=<br />

28g<br />

/ mol<br />

= 0.179mol<br />

Limiting Reagent<br />

0.720mol<br />

Li=<br />

= 0.120<br />

6<br />

0.179mol<br />

N<br />

2<br />

= = 0.179<br />

1<br />

Limiting Reagentis Li<br />

2Li3N<br />

x<br />

=<br />

6Li<br />

0.720mol<br />

x = 0.240 mol Li<br />

3<br />

N<br />

gLi N = 0.240mol(34.82g<br />

/ mol)<br />

3<br />

= 8.35g

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