MCQ Flashcards
(30 cards)
What is the SI unit for entropy
- Joule/ Kelvin
- Joule
- Joule/Mole
- Joule/Kg
- L/Kelvin
- Joule/Kelvin
The free engery change is zero in…
- the state of equilibrium
- spontaneous reactions
- reversible reactions
- atomic and ionic reactions
- autocatalytic reactions
- the state of equilibrium
How does the catalyst change the reaction rate?
- increase the value of the equilibrium constant
- increases the free energy change
- decreases the activation energy
- decreases the value of the rate constant
- decreases the activation energy
5. decreases the value of the rate constant
Which of the followings has an influence on the rate constant of a chemical reaction?
- the kinetic order of the reaction
- the molecularity of the reaction
- the temperature
- the energy of activation
- the kinetic order of the reaction
- the molecularity of the reaction
- the temperature
An iron plate submerged into AgNO3 solution gets coated by silver. What happens?
- iron is oxidized into Fe2+ ions .
- Ag+ ions are reduced and the plate is coated by Ag.
- iron is oxidized into Fe3+ ions.
- Ag+ ions are oxidized and the plate is coated by Ag.
- iron is oxidized into Fe2+ ions .
2. Ag+ ions are reduced and the plate is coated by Ag.
What are the possible ways of reduction?
- uptake of hydrogen
- uptake of electrons
- decrease of negative charges
- removal of oxygen
- uptake of hydrogen
2. uptake of electrons
What are the names of the rings fused in purine backbone?
- pyrimidine and imidazole
- pyridine and imidazole
- pyridine and pyrimidine
- pyrazine and pyrrol
- pyrimidine and pyriazine
- pyrimidine and imidazole
Which of the following compounds contains two hetero atoms?
- pyrimidine
- pyrrole
- pyran
- pyridine
- furan
- pyrimidine
Which statements are true for alcohols?
- Their boiling point is higher than that of alkanes with the same carbon skeleton.
- Long chain alcohols are completely miscible with water due to their ability to form hydrogen bonds.
- The conjugate base of an alcohol is the alkoxide anion.
- Aliphatic alcohols are stronger acids than phenols.
- Electron whitdrawing groups increase the acidity of alcohols by stabilizing their conjugate bases
- Their boiling point is higher than that of alkanes with the same carbon skeleton.
- The conjugate base of an alcohol is the alkoxide anion.
- Electron whitdrawing groups increase the acidity of alcohols by stabilizing their conjugate bases.
What is a typical reaction of aldehydes?
- nucleophilic addition
- electrophilic addition
- radical addition
- electrophilic substitution
- nucleophilic substitution
- nucleophilic addition
What is the common name of the compounds containing a hydroxyl group linked directly to the aromatic ring?
- phenols
- enols
- aromatic alcohols
- thiols
- hydroxols
- phenols
What is the maximal number of electrons in the first shell characterized by principal quantum number 1 ?
a: 6
b: 4
c: 8
d: 1
e: 2
e: 2
Select the correct statement:
- the H and the Cl atoms form a covalent bond in the HCl molecule.
- the dipole moment of HCl molecule in the gas phase is zero.
- the H and the Cl atoms form an ionic bond in the HCl molecule.
- the H and the Cl atoms form a dative bond in the HCl molecule
- the H and the Cl atoms form a hydrogen bond in the HCl molecule
- the H and the Cl atoms form a covalent bond in the HCl molecule.
Which statements are true for the ionic bond?
- binding electrons are shared by the two atoms
- the components are kept togehter by electrostatic forces
- the dipole momentum of the ionic compounds is zero
- the components are kept togehter by electrostatic forces
Which of the statements below are correct?
- the water solubility of solid crystalline compounds usually decreases by the increasing temperature
- the water solubility of solid crystalline compounds usually increases by the increasing temperature
- the water solubility of gases usually decreases by the increasing temperature
- the water solubility of gases usually increases by the increasing temperature
- the water solubility of gases does not depend on the temperature
- the water solubility of solid crystalline compounds usually increases by the increasing temperature
- the water solubility of gases usually decreases by the increasing temperature
What may happen to the red blood cells in hypotonic solution?
- the cells shrink
- their membrane ruptures leading to hemolysis
- they maintain their discoid shape
- they take up water and swell
- their membrane ruptures leading to hemolysis
4. they take up water and swell
Select the compound(s) from the list below that decrease(s) the dissociation of phosphoric acid, when added in 0,1M concentration to a 0,1M phosphoric acid solution?
- NaOH
- Na2SO4
- Na2CO3
- H2SO4
- H2SO4
What is the formula for chlorous acid?
- HCl
- HClO
- HClO2
- HClO3
- HClO4
- HClO2
What is the formula for nitric acid?
- HNO3
- HON3
- HNO2
- H2HO3
- H2NO4
- HNO3
Which of the following compounds has/have geometric isomers?
- ethane
- ethene
- 2-butene
- 1-butene
- 2-butene
Which of the following compounds contain more than one chiral center?
- citrate
- tartarate
- isocitrate
- 1,2-dimethylcyclohexane
- tartarate
- isocitrate
- 1,2-dimethylcyclohexane
Which of the following statements are true for ethene?
- all the bond types are covalent sigma bonds
- the hybrid state of the carbons is sp3.
- its characteristic reaction is electrophilic addition
- the saturation of ethene with bromide proceeds via a radical reaction mechanism catalyzed by UV light.
- during saturation of ethene with bromine a cyclic intermediate is formed
- its characteristic reaction is electrophilic addition
5. during saturation of ethene with bromine a cyclic intermediate is formed
Which of the following compounds has positional isomers?
- butene
- ethene
- ethane
- acetaldehyde
- naptalene
- butene
At which of the following concentrations does HCOOH have the highest degree of ionization?
- 0,1 N
- 0,01 N
- 0,001 N
- 1 N
- The degree of ionization does not depend on the concentration
- 0,001 N