OrgChem-2019 Flashcards
- Which of the following compounds has an Ionic bond?
I. H2O
II. NH4Cl
III. CH3Cl
IV. CH3Li
A. II
B. IV
C. I
D. III
A. II
- How many hydrogen atoms are in one molecule of propene?
A. 4
B. 3
C. 6
D. 8
C. 6
- In which species are all the carbon atoms considered to be sp2 hybridized?
l. C2H2
II. C2H4
Ill. C3H8
IV. C4H10
A. IV
B. Il
C. I
D. Ill
B. Il
- For which compound are the empirical and molecular formulas the same?
I —- C6H5COOH
II —- C6H4(COOH)2
III —- HOOCCOOH
IV —- CH3COOH
A. Ill
B. I
C. IV
D. II
B. I
- What Is the hybridization of the carbon atom in a carboxyl group?
A. sp
B. sp3
C. sp2
D. dsp3
C. sp2
- How many different compounds have the formula C5H12?
A. 5
B. 2
C. 4
D. 3
D. 3
- How many different alcohols have the molecular formula C4H10O?
A. 2
B. 4
C. 3
D. 5
B. 4
- Which compound Is expected to be most soluble in water at 25oC
I —- N2 (g)
II —- O2 (g)
III —- (C2H5)2NH (l)
IV —- C2H5OC2H5 (l)
A. III
B. IV
C. I
D. II
A. III
- In which species Is the carbon-nitrogen bond the shortest?
I. CH3NH2
II. CH2NH
Ill. (CH3)4N+
IV. CH3CN
A. Il
B. I
C. IV
D. Ill
C. IV
- the gentle oxidation of ethanol (CH3CH2OH) produces ______
I — ethanal, CH3CHO
II — ethanoic acid,
III —carbon monoxide, CO
IV — carbon dioxide, CO2
A. IV
B. I
C. II
D. III
B. I
- The following compounds have very similar molar masses. What would be the correct order when they
are arranged in order of increasing strength of their intermolecular forces.
l. C3H8
Il. CH3OCH3
III. CH3CH2OH
A. II < I < III
B. III < I < II
C. I < II < III
D. III < II < I
C. I < II < III
- The process of heating a liquid mixture to form vapors and then cooling the vapors to get a pure
component is called
A. Distillation
B. Chromatography
C. Crystallization
D. Sublimation
A. Distillation
- Which of the following hydrocarbon has the lowest boiling point?
l. C4H10
ll. CH4
Ill. C6H6
IV. C2H6
A. IV
B. II
C. I
D. III
B. II
- In crystallization, the solution which is obtained after filtration is the
A. clear solution
B. colloidal solution
C. suspended solution
D. None of the given answers
A. clear solution
- A reaction in which a carboxylic add reacts with an alcohol to form an organic compound and water Is
called
A. saponification
B. esterification
C. neutralization
D. hydrolysis
B. esterification
- A constant boiling mixture of two in a solution is called a/an _______
A. azeotrope
B. Ideal
C. non-ideal solution
D. eutectic mixture
A. azeotrope
- Which separation technique is based in the volatility of the compounds to be separated?
A. solvent extraction
B. distillation
C. paper chromatography
D. filtration
B. distillation
- What is the position of the bromine atom relative to the methyl group in 3-bromotoluene?
A. meta
B. para
C. ortho
D. trans
A. meta
- Which combination of reactants produces an ester?
A. aldehyde and potassium permanganate
B. acid and alcohol
C. acid and aldehyde
D. alcohol and aldehyde
B. acid and alcohol
- Five grams an organic solid was dissolved in 100 mL of distilled water. Which of the following extraction
methods can remove the largest amount of organic solid from an aqueous solution?
A. Extract the aqueous solution with a 150-mL portion of ether.
B. Extract the aqueous solution with three 50-mL portions of ether.
C. Extract the aqueous solution with a 150-mL portion of acetic acid.
D. Extract the aqueous solution with three 50-mL portions of acetic acid.
B. Extract the aqueous solution with three 50-mL portions of ether.
- Which class of compounds consist exclusively of saturated hydrocarbons?
A. alkenes
B. aromatics
C. alkynes
D. alkanes
D. alkanes
- The smell of rancid butter is due to the presence of butyric (butanoic) acid. What is the for this
compound?
I — C4H8O2
II — C4H10O
III — C5H10O2
IV — C5H12O
A. IV
B. II
C. III
D. I
D. I
- A common measure of efficiency in a fractionating column is the
A. length of the condenser used in the setup
B. number of distillation types
C. number of components in the solution
D. number of theoretical plates in the column
D. number of theoretical plates in the column
- In crystallization, the crystal phases can be Inter-converted by varying ______
A. temperature
B. pressure
C. viscosity
D. size
A. temperature
- Fractional distillation is different from distillation because of the presence of a _______
A. Fractionating column
B. Condenser
C. Conical flask
D. Distillation flask
A. Fractionating column
- Which of the following is the example of crystallization process?
A. Purification of alum
B. None of the given answers
C. Separation of gases from air
D. Purification of sea water
A. Purification of alum
- What is the key step in a recrystallization process?
A Taking the melting point of wet crystals
B. Dissolving the solid in a large quantity of cold solvent
C. Allowing the hot solution to cool slowly and let crystals grow
D. Removing the soluble impurities by vacuum filtration
C. Allowing the hot solution to cool slowly and let crystals grow
- Which is the INCORRECT statement among the following?
A. An impure sample of the substance has a different melting point.
B. Two different pure substances have the same melting points.
C. Melting point serves as the criterion of purity of a solid substance.
D. Every pure crystalline substance has a characteristic and unique melting point.
B. Two different pure substances have the same melting points.
- When the solid and liquid phases are in equilibrium, the temperature of the system
A. decreases gradually
B. none of the given answers
C. Increases gradually
D. remains constant
D. remains constant
- Which of the following statements is correct?
A. Solid reactants can be weighed directly in the weighing pan of the analytical balance
B. Weight of liquids is approximately equal to its density.
C. Solid reactants can be transferred to a reaction flask by using a metal spatula.
D. Volatile liquids can be weighed by getting the mass of the empty vial with cap first.
D. Volatile liquids can be weighed by getting the mass of the empty vial with cap first.
- Which of the following funnels should be used to filter hot mother liquor during recrystallization?
A. Buchner funnel
B. Hirsch funnel
C. Long stem funnel
D. Short stem funnel
D. Short stem funnel
- A compound Is known to decompose at its boiling point. Which of the following can be to purity this
substance?
A. Steam distillation
B. Fractional distillation
C. Liquid-liquid extraction
D. Vacuum distillation
A. Steam distillation
- The boiling point of a liquid is the temperature at which the vapor pressure is ______
A. lesser than internal pressure
B. equal to internal pressure
C. equal to external pressure
D. greater than internal pressure
C. equal to external pressure
- A reaction mixture needs to be cooled to -77*C after refluxing. What Is the best method to be used?
A. Place the reaction vessel in an ice bath.
B. Place the reaction vessel in the freezer.
C. Place the reaction vessel in a salt and crushed ice mixture
D. Place tie reaction mixture in a dry ice-acetone mixture.
D. Place tie reaction mixture in a dry ice-acetone mixture.
- Which of reactions will consume the most oxygen?
A. complete combustion one mole of octane
B. complete combustion of one mole of 2,3-dimethylhexane
C. complete combustion of one mole of 2,3,4-trimethylpentane
D. All the given compounds win consume the same amount of oxygen.
D. All the given compounds win consume the same amount of oxygen.
- Which of the following techniques can be used to heat a reaction to 200*C?
A. Use a Bunsen burner to heat the reaction vessel.
B. use a heating mantle with stirring.
C. Place the reaction vessel in a sand bath with stirring.
D. Place the reaction vessel in a water bath with stirring.
C. Place the reaction vessel in a sand bath with stirring.