# When 500 g of acetylene is allowed to react with excess...

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Exam 2 1307-S2019-A.pdf

1 )   When 50.0 g of acetylene is allowed to react with excess oxygen , 75. 0 g of CO 2 are formed . What is the percent yield of carbon dioxide ? 2C 2 H 2 ( g ) + 5O 2 ( g ) → 4 CO 2 ( g ) + 2H 2 O ( g ) acetylene
A ) 150. %
B ) 44.4 %
C ) 100. %
D ) 6.7 %
E ) 88.8 %
3 )   How many moles of H + ( aq ) ions are present in 250 . m L of 1.15 M hydrochloric acid ?
4 )   Which one of the following compounds is insoluble in water ?
5 )   Ethylene glycol , used as a coolant in automotive engines , has a specific heat capacity of 2.42 J/g°C. Calculate q when 3.65 kg of ethylene glycol is cooled from 132.° C to 85.° C.
6 )   The volume of a gas with a pressure of 1.2 atm increases from 1.0 L to 4.0 L. What is the final pressure of the gas , assuming constant temperature ?
A ) 0.30 atm
B ) 4.8 atm
C ) 1.2 atm
D ) 3.3 atm
E ) 1.0 atm
7 )   Automobile batteries use 3.0 M H 2 SO 4 as an electrolyte . How much 1.20 M NaOH will be needed to neutralize 225 . m L of battery acid ? H 2 SO 4 ( aq ) + 2 NaOH ( aq ) → 2H 2 O ( l ) + Na 2 SO 4 ( aq )
8 )   Magnesium ( used in the manufacture of light alloys ) reacts with iron ( III ) chloride to form magnesium chloride and iron . A mixture of 1.687 mols of magnesium and 1.079 mols of iron ( III ) chloride is allowed to react . Identify the limiting reactant and determine the mass of the excess reactant present in the vessel when the reaction is complete .
9 )   What is the density of Ar ( g ) at – 11 ° C and 675 mm Hg ( 1 atm = 760 mm Hg )
10 )   For the reaction of carbon dioxide to form carbon monoxide and oxygen , Δ H is + 570 kJ . This reaction is 2 CO 2 ( g ) → 2CO ( g ) + O 2 ( g ) Δ H= + 570 k J
A ) combination
B ) oxidation
C ) exothermic
D ) endothermic
E ) double replacement
11 )   Which gas has molecules with the greatest average molecular speed at 25 ° C ?
12 )   In which process is Δ H = Δ E ?
13 )   At STP , temperature and pressure have the values of
14 )   What is Δ H ° rxn for the reaction 2 Al 2 O 3 ( s ) → 4 Al ( s ) + 3O 2 ( g ) ? Δ H ° f ( Al 2 O 3 ( s ) ) = – 1670 kJ / mol
A ) 3340 kJ / mol
B ) 1670 kJ/mol
C ) – 3340 kJ / mol
D ) – 835 kJ / mol
E ) – 1670 kJ / mol
CHEM 1307 Spring 2019 Midterm Exam #2 MULTIPLE CHOICE. Select the one choice that best completes the statement or answers the question. 1) When 50.0 g of acetylene is allowed to react with excess oxygen, 75.0 g of CO 2 are formed. What is the percent yield of carbon dioxide? 2C 2 H 2 ( g )+ 5O 2 ( g ) 4CO 2 ( g ) + 2H 2 O( g acetylene ) A) 150.% B) 44.4% C) 100.% D) 6.7% E) 88.8%
2) Which of these chemical equations describes a precipitation reaction ? ) ) ) ) )
3) How many moles of H + ( aq ) ions are present in 250. mL of 1.15 M hydrochloric acid?
4) Which one of the following compounds is insoluble in water?
5) Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 J/g°C. Calculate q when 3.65 kg of ethylene glycol is cooled from 132.°C to 85.°C. A) –99. kJ B) 4.2 × 10 6 kJ C) –0.42 kJ D) –1.9 x 10 3 kJ E) –4.2 x 10 2 kJ
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6) The volume of a gas with a pressure of 1.2 atm increases from 1.0 L to 4.0 L. What is the final pressure of the gas, assuming constant temperature?
7) Automobile batteries use 3.0 M H 2 SO 4 as an electrolyte. How much 1.20 M NaOH will be needed to neutralize 225. mL of battery acid? H 2 SO 4 ( aq ) + 2NaOH( aq ) 2H 2 O( l ) + Na 2 SO 4 ( aq )
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