CHEMICAL TECHNICIAN Licensure Examination Flashcards
Organic Chemistry
Which of the following compounds has an ionic bond?
A. H2O
B. NH4Cl
C. CH3Cl
D. CH3Li
B. NH4Cl
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?
A. C2H2
B. C2H4
C. C3H6
D. C4H10
B. C2H4
For which compound are the empirical and molecular formulas the same?
A. C6H5COOH
B. C5H4(COOH)2
C. HOOCCOOH
D. CH3COOH
A. C6H5COOH
How many different compounds have the formula C5H12?
A. 5
B. 2
C. 4
D. 3
D. 3
In which species is the carbon-nitrogen bond the shortest?
A. CH3NH2
B. CH2NH
C. (CH3)4N+
D. CH3CN
D. CH3CN
What is the hybridization of the carbon atom in a carboxyl group?
A. sp
B. sp3
C. sp2
D. dsp3
C. sp2
Which of the following hydrocarbon has the lowest boiling point?
A. C4H10
B. CH4
C. C6H6
D. C2H6
B. CH4
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 25°C?
A. N2
B. O2 (g)
C. (C2H5)2NH (l)
D. C2H5OC2H5 (l)
D. C2H5OC2H5 (l)
The gentle oxidation of ethanol, CH3CH2OH produces _____________.
A. ehtanal, CH3CHO
B. ethanoic acid, CH3CO2H
C. carbon monoxide, CO
D. carbon monoxide, CO2
A. ehtanal, CH3CHO
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 molecular forces?
I. C3H8
II. CH3OCH3
III. CH3CH2OH
A. II < I < III
B. III < I < II
C. I < II < III
D. III < II < I
C. I < II < III
A reaction in which a carboxylic acid reacts with an alcohol to form an organic compound and water is called _____________.
A. saponification
B. esterification
C. neutralization
D. hydrolysis
B. esterification
Which class of compounds consists exclusively of saturated hydrocarbons?
A. alkenes
B. aromatics
C. alkynes
D. alkanes
D. alkanes
What is the position of the bromine atom relative to the methyl group in 3-bromotluene?
A. meta
B. para
C. ortho
D. trans
A. meta
The smell of rancid butter is due to the presence of butyric (butanoic) acid. What is the formula for this compound?
A. C4H8O2
B. C4H10O
C. C5H10O2
D. C5H12O
A. C4H8O2
Which combination of reactant produces an ester?
A. aldehyde and potassium permanganate
B. acid and alcohol
C. acid and aldehyde
D. alcohol and aldehyde
B. acid and alcohol
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
D. none of the given answers
In crystallization, the crystal phases can be inter-converted by varying ________.
A. temperature
B. pressure
C. viscosity
D. size
A. temperature
Which separation technique is based on differences in the volatility of the compounds to be separated?
A. solvent extraction
B. distillation
C. paper chromatography
D. filtration
B. distillation
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
The process of heating a liquid mixture to from vapors and then cooling the vapors to get a pure component us called ____________.
A. Distillation
B. Chromatography
C. Crystallization
D. Sublimation
A. Distillation
A common measure of efficiency in a fractioning 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
Five grams of 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 of the following funnels should be used to filter hot mother liquid during recrystallization?
A. Buchner funnel
B. Hirsch funnel
C. Long stem funnel
D. Short stem funnel
A. Buchner funnel
What is the key step in 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
D. Removing the soluble impurities by vacuum filtration
Which of the following is the example of crystallization process?
A. Purification of alum
B. Purification of sea water
C. Separation of gases from air
D. None of the given answers
A. Purification of alum
A constant boiling mixture of two or more components in a solution is called a/an _____________.
A. azeotrope
B. ideal solution
C. non-ideal solution
D. eutectic mixture
A. azeotrope
A compound is known to decompose at its boiling point? Which of the following methods can be used to purify this substance?
A. Steam distillation
B. Fractional distillation
C. Liquid-liquid extraction
D. Vacuum distillation
D. Vacuum distillation
When the solid and liquid phases are in equilibrium, the temperature of the system ________________.
A. decreases gradually
B. remains constant
C. increases gradually
D. none of the given answers
B. remains constant
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 solid crystalline substance has a characteristic and unique melting point.
B. Two different pure substances have the same melting points.
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
B. equal to internal pressure
Which of the following statement is correct?
A. Solid reactant 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.
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 the reaction mixture in a dry ice-acetone mixture.
D. Place the reaction mixture in a dry ice-acetone mixture.