WorksheetsChemistry Midterm 2
Total questions: 70
Worksheet time: 35mins
What substances are called isomers?
Substances with the same molecular formula but different physical states.
Substances with different molecular formulas but similar physical states.
Substances with the same molecular formula but different structures.
Substances with different molecular formulas and physical states.
Which functional groups does the composition of 2-hydroxy-4-methylbenzoic acid include?
Hydroxyl and carboxyl groups.
Carboxyl and methyl groups.
Hydroxyl, methyl, and carboxyl groups.
Alcohol and ester groups.
Name the compound using IUPAC substitutive nomenclature: Example Compound: CH3-CH(OH)-COOH
Lactic acid.
2-hydroxypropanoic acid.
Propanoic acid.
3-hydroxybutanoic acid.
Indicate the definition of homologues.
Compounds with identical structures but varying physical properties.
Compounds with the same chemical properties but different molecular formulas.
Members of a chemical series that differ by a CH2 unit.
Organic compounds having the same molecular formula but different structures.
One of the reasons for the diversity of organic substances.
The unique properties of carbon to form bonds.
Presence of diverse inorganic elements.
The interaction of metallic atoms.
The reactivity of oxygen in compounds.
The carboxyl group contains molecules:
-COOH group.
-OH group.
-CHO group.
-CO group.
Xylitol, called pentanol-1,2,3,4,5 according to the IUPAC substitution nomenclature, is used as a sugar substitute for patients with diabetes. Choose true statements:
It has no caloric value.
It does not spike blood glucose levels.
It is metabolized without the need for insulin.
Both b and c are correct.
Are the following statements true about the chemical structure of organic substances? 1.Chemical structure shows the spatial arrangement of atoms in molecules of a compound. 2.The mutual influence of atoms determines the chemical properties of the molecule.
Both statements are true.
Only the first statement is true.
Only the second statement is true.
Both statements are false.
How is a group of atoms called that determine the characteristic chemical properties of a given class of substances?
Functional group.
Isomers.
Substituents.
Radicals.
The process of combining many identical molecules into larger ones without the formation of by-products is called:
Addition reaction.
Polymerization.
Condensation.
Crystallization.
How is the displacement of electron density along a chain of single (σ) bonds called?
Resonance effect.
Inductive effect.
Hyperconjugation.
Conjugation effect.
How many functional groups does the composition of 2-hydroxy-4-methylbenzoic acid include?
One.
Two.
Three.
Four.
Which substituents can have a positive inductive effect?
Electronegative groups like -NO2.
Groups that donate electrons, like -CH3.
Halogens like -Cl.
None of the above.
Which type of enantiomers have monosaccharides that are involved in vital processes?
D-enantiomers.
L-enantiomers.
Both D- and L-enantiomers.
None of these.
Give a name to the carbon atom bonded to four different atoms or groups.
Symmetric carbon.
Chiral carbon.
Stereoisomer.
Alkyl carbon.
Which projection formulas are used to depict conformations?
Fisher and Haworth projections.
Newman and Fischer projections.
Newman and Sawhorse projections.
Haworth and Kekulé structures.
Name the influence of a substituent that is transmitted along a chain of π-bonds.
Resonance effect.
Inductive effect.
Hyperconjugation.
Conjugation effect.
Give a name to particles or neutral molecules that have a pair of electrons in the outer electronic level.
Anions.
Cations.
Electrophiles.
Nucleophiles.
Specify the formula for a compound with conjugated double bonds:
C6H12.
C2H4.
C6H6.
CH2=CH-CH=CH2.
Determine the compound that is used as a configuration standard relatively in D-, L- nomenclature.
Glyceraldehyde.
Glucose.
Lactic acid.
Amino acid.
From the following compounds determine the compound that will be used in a qualitative reaction to polyatomic alcohols:
Ethanol.
Methanol.
Glycerol.
Propanol.
Ethyl alcohol can be obtained by hydrolysis of ethyl bromide. What is the mechanism of this reaction?
Nucleophilic substitution (SN1 or SN2).
Electrophilic addition.
Free-radical mechanism.
Elimination (E1 or E2).
What product is formed during the oxidation of propanol-1?
Propane.
Propanal.
Propanoic acid.
Both b and c.
Establish the reaction mechanism: CH3CH=CH2 + H2O → (H⁺) → CH3CH(OH)CH3
Electrophilic addition.
Free radical substitution.
Elimination reaction.
Nucleophilic substitution.
What does the oxidation of primary alcohols produce?
Ketones.
Aldehydes, and further carboxylic acids.
Alkanes.
Alkenes.
Penicillamine is an antidote used for poisoning with heavy metal compounds. Give it a name according to the IUPAC substitutive nomenclature:
β-Mercapto-α-aminoisobutyric acid.
β-Amino-α-mercaptoisobutyric acid.
α-Amino-β-mercaptoisobutyric acid.
β-Amino-γ-mercaptoisobutyric acid.
Indicate the negatively charged ions and neutral molecules with a free pair of electrons.
Nucleophiles.
Electrophiles.
Radicals.
Carbocations.
From the following compounds indicate the polyatomic alcohols.
Methanol, ethanol.
Propanol, butanol.
Glycerol, xylitol.
Phenol, cresol.
Which reactions are most characteristic for compounds containing halogen, hydroxyl, thiol, and amino groups?
Addition reactions.
Nucleophilic substitution and elimination reactions.
Free-radical substitution reactions.
Dehydration reactions.
Give a name to the rule that has the formulation, “In elimination reactions, the preferential removal of a proton occurs from the least hydrogenated carbon atom.”
Markovnikov’s rule.
Zaitsev’s rule.
Hofmann’s rule.
Saytzeff’s rule.
What particles are formed during the heterolytic cleavage of a covalent bond in a reagent molecule?
Free radicals.
Cations and anions.
Neutral molecules.
Electrophiles and nucleophiles.
Which of the following formulas contain carbon atoms in the state of sp³ hybridization?
Only 1.
1 and 3.
1, 3, and 4.
2 and 4.
Considering the properties of organic compounds, we can distinguish two types of influence of substituents on the electron density of the carbon chain. Which of these is called an inductive effect? Does it decay quickly or slowly as it propagates through the circuit?
Through π-bonds; decays quickly.
Through σ-bonds; decays quickly.
Through π-bonds; decays slowly.
Through σ-bonds; decays slowly.
From what unsaturated hydrocarbon can benzene be synthesized, and what amount of the substance is involved in the reaction?
Ethylene, 3 molecules.
Acetylene, 3 molecules.
Propylen, 2 molecules.
Butadiene, 2 molecules.
What types of reactions are most typical for benzene, and through what bond do they occur?
Addition reactions through π-bonds.
Electrophilic substitution through π-bonds.
Free-radical substitution through σ-bonds.
Nucleophilic substitution through σ-bonds.
What is the main product formed during the hydration of butene-1?
1-Butanol.
2-Butanol.
Butanal.
Butanoic acid.
A compound of the CH3−X type, where X is an atom of chlorine, bromine, iodine, or fluorine. Arrange in a row where the polarity of the bond increases.
CH3-I < CH3-Br < CH3-Cl < CH3-F
CH3-F < CH3-Cl < CH3-Br < CH3-I
CH3-Cl < CH3-Br < CH3-I < CH3-F
CH3-F < CH3-I < CH3-Cl < CH3-Br
The interaction of methane with chlorine in the light proceeds according to the reaction: CH4 + Cl2 → CH3Cl + HCl. Which of the following stages is not the termination stage?
CH3 + Cl → CH3Cl.
Cl + Cl → Cl2.
CH3 + CH3 → C2H6.
Cl2 → 2Cl (under UV light).
What does the arrow mean that is located between atoms in the formula CH3→CH2→Br?
Inductive effect.
Resonance effect.
Hyperconjugation.
Dipole moment.
Which of the following compounds exhibits the conjugation effect?
Propane.
Benzene.
Ethane.
Cyclopropane.
What are the correct names of the following carboxylic acids? 1.СН3-СН(ОН)-СООН 2.СН3-СО-СООН 3.СН3-СН(СН3)-СООН
1) Lactic acid, 2) Pyruvic acid, 3) Isobutyric acid.
1) Acetic acid, 2) Pyruvic acid, 3) Lactic acid.
1) Malic acid, 2) Acetic acid, 3) Isobutyric acid.
1) Tartaric acid, 2) Succinic acid, 3) Propanoic acid.
The characteristic violet color for the biuret reaction appears when biuret reacts with:
Copper sulfate (CuSO4).
Sodium hydroxide (NaOH).
Ammonia solution.
Potassium dichromate.
Dibasic carboxylic acids are stronger than monobasic acids because:
They have two acidic protons.
Their molecular weight is higher.
They dissociate more completely in water.
Their conjugate bases are stronger.
Urea, the most important nitrogen-containing end product of human metabolism, can be opened by the biuret reaction. In this reaction, biuret is obtained by heating urea slowly. What degree of heating does urea require?
50–60°C.
110–120°C.
140–150°C.
170–180°C.
Benzoic acid is well nitrated with nitric acid. In what position of the aromatic ring is the nitro group introduced?
Ortho position.
Meta position.
Para position.
Both ortho and para positions.
By what reaction can malonic acid be distinguished from succinic acid?
Titration with a strong base.
Decarboxylation reaction.
Reaction with bromine water.
Esterification with ethanol.
Indicate an equation of the reduction of pyruvic acid into lactic acid that proceeds in the body.
CH3COCOOH → CH3CHOHCOOH (in the presence of NADH).
CH3COOH → CH3CHO.
CH3CH2COOH → CH3CHOHCH2OH.
CH3COCOOH → CH3CH2COOH.
Determine the product that will be formed during the decarboxylation in vivo of 2-amino-3-hydroxypropanoic acid.
Acetone.
Ethanol.
Ethanolamine.
Lactic acid.
Indicate the final product of ethanol oxidation in the body.
Acetaldehyde.
Acetic acid.
Carbon dioxide and water.
All of the above.
Antifebrine (acetanilide) is an N-phenylacetamide and it is known as one of the first antipyretics. What reagents can be used for its synthesis?
Aniline and acetic acid.
Aniline and acetyl chloride.
Phenol and acetic acid.
Phenol and acetyl chloride.
Indicate the polysaccharide that contains a disaccharide fragment, including D-glucuronic acid (β-1,3) and N-acetyl-2-D-glucosamine (β-1,4):
Starch.
Cellulose.
Hyaluronic acid.
Glycogen.
What kind of glycosidic bond does the structure of heparin contain?
α-1,4.
β-1,3.
α-1,3 and α-1,4.
β-1,6.
Cellulose forms esters by interacting with which compounds?
Acids and alcohols.
Acids and anhydrides.
Bases and alcohols.
Acids and thiols.
From the following given compounds, choose those that heteropolysaccharides include: 1.Glycogen. 2.Heparin. 3.Amylose. 4.Chondroitin sulfate. 5.Hyaluronic acid.
1, 3.
2, 4, 5.
1, 2, 5.
2, 3, 4.
Modern ideas about photosynthesis: . One of these statements is erroneous. Please indicate the error:
Water acts as a reducing agent.
Oxygen is released from carbon dioxide.
Glucose is the final product of photosynthesis.
Light energy is essential for the reaction.
Choose the bonds from the following types of glycosidic bonds that are characteristic of starch:
α-1,4 and α-1,6.
α-1,6 and β-1,4.
β-1,4 and β-1,3.
α-1,3 and β-1,4.
Determine the final product of cellulose hydrolysis:
Glucose.
Maltose.
Sucrose.
Fructose.
What special property does starch have, differentiating it from cellulose?
It forms esters more easily.
It reacts with iodine to form a blue complex.
It undergoes acid hydrolysis to form xylose.
It cannot be digested by amylase enzymes.
Which functions does starch perform in plant cells?
Structural role.
Energy storage.
Transport of nutrients.
Enzymatic activity.
Specify the enzyme that is used in starch hydrolysis in the body:
Cellulase.
Amylase.
Maltase.
Sucrase.
Macromolecules of peptides and proteins are built from residues of which compounds?
Monosaccharides.
Fatty acids.
α-amino acids.
Nucleotides.
The primary structure of a protein:
The sequence of amino acids.
The folding of polypeptide chains.
The arrangement of protein subunits.
The interaction of proteins with water.
Due to what bonds is the quaternary structure of proteins formed?
Peptide bonds.
Hydrogen bonds and disulfide bridges.
Ionic bonds and van der Waals forces.
Both b and c.
Due to what enzymes does the breakdown of proteins occur in the animal body?
Lipases.
Amylases.
Proteases.
Isomerases.
From the following given properties, choose the properties of peptides and proteins at the isoelectric point: 1.Least stable. 2.Negatively charged molecules. 3.Easy to settle. 4.Positively charged molecules. 5.Total charge of the molecule equal to zero.
1, 3.
2, 4.
1, 5.
1, 2.
Proteins differ from peptides:
By having a higher molecular weight.
By containing more than 50 amino acids.
By having complex secondary and tertiary structures.
All of the above.
Indicate the qualitative reaction to a peptide bond:
Ninhydrin reaction.
Biuret reaction.
Iodine test.
Molisch reaction.
What chemical reaction occurs as the specific detection of cysteine residues in proteins, if the reaction of a protein molecule with Pb²⁺ can be represented as follows:
Biuret test.
Xanthoproteic test.
Lead acetate test.
Iodine test.
Name the given dipeptide: Structure: H2N-CH(CH3)-CONH-CH(C6H5)-COOH.
Leucylphenylalanine.
Alanylphenylalanine.
Glycylphenylalanine.
Valylphenylalanine.
Where does the breakdown of proteins into peptides occur in living organisms?
Liver.
Stomach and small intestine.
Large intestine.
Blood plasma.
