Zagreb MSE Entrance Exam Example – Chemistry

Which of the following will NOT give homogenous mixture when mixed with water?
- olive oil
- table sugar
- vinegar
- ethyl alcohol
- table salt
What is the mass of one mole of an element represented by the electron configuration 1s²2s²2p⁶3s²3p⁶4s¹?
- 23.0 g
- 24.3 g
- 39.1 g
- 40.1 g
- 6.5·10^–23 g
If 0.5 moles of calcium carbonate are thermally decomposed to calcium oxide and carbon(IV) oxide, calculate the volume of carbon(IV) oxide produced under standard temperature and pressure?
- 11.2 L
- 1.0 L
- 22.4 L
- 44.8 L
- 5.6 L
Find the correct statement regarding the periodic properties of the main group elements.
- Ionization energy increases going from sodium towards caesium within a group.
- Atomic radius decreases going from sodium towards fluorine within a second period.
- Electronegativity increases going from oxygen towards tellurium within a group.
- Ionization energy decreases going from magnesium towards chlorine within third period.
- Electron affinity increases going from nitrogen towards bismuth within a group.
The exothermic process O²(g) → O²(aq) will be spontaneous when:
- ΔH – TΔS < 0
- ΔH = TΔS
- ΔG < TΔS
- ΔG > 0
- ΔS > TΔH
What of the listed is NOT phase change?
- C₆H₆(l) → C₆H₆(g)
- I₂(s) → I₂(g)
- NaBr(s) → Na⁺(aq) + Br^-(aq)
- KI(s) → KI(l)
- C₅H₅N(l) → C₅H₅N(s)
Water (W), dimethyl sulfoxide (D) and cyclohexane (C) are solvents whose densities at 20°C are ρ(C₆H₁₂) = 0.78 g/mL, ρ(H₂O) = 1.00 g/mL and ρ(C₂H₆OS) = 1.10 g/mL, respectively. It is known that water and dimethyl sulfoxide are miscible with each other, while cyclohexane is immiscible either with water or dimethyl sulfoxide. Which of the following figures represents the mixture obtained after shaking together 1 mL of water, 1 mL of dimethyl sulfoxide and 1 mL of cyclohexane?
- figure 1
- figure 2
- figure 3
- figure 4
- figure 5
Alcohol is produced by:
- reduction of ketone
- amino acid hydrolysis
- reaction of amine with water
- esterification
- oxidation of acetal
What is the difference between boiling and evaporation (for a given pressure)?
- Evaporation occurs at a particular temperature only, while boiling may occur at a range of temperatures.
- Boiling occurs at a particular temperature only, while evaporation may occur at a range of temperatures.
- At boiling point the liquid is changed into a gas without an external source of heat, while evaporation needs external source of heat in order for liquid to change into gas.
- Boiling occurs at surface of liquid only, while evaporation occurs throughout the liquid.
- There is no difference between boiling and evaporation since in each case a liquid is changed into a gas.
What gas forms at the cathode during the electrolysis of water? How many milligrams of the gas are produced at the cathode after electrolyzing the water for 10 minutes at a current of 100 mA?
- oxygen; 4.97
- hydrogen; 10.5
- hydrogen; 1.25
- oxygen; 82.9
- hydrogen; 0.63
Average rain water (unpolluted rain) is slightly acidic as a result of dissolved:
- oxygen
- methane
- carbon dioxide
- sulphur dioxide
- nitrogen dioxide
Classify the type of all reactions shown below.
- 1C, 2B, 3B
- 1B, 2A, 3C
- 1A, 2B, 3C
- 1C, 2A, 3B
- 1A, 2A, 3C
Which one of the following metals reacts vigorously with oxygen and water?
- aluminium
- copper
- iron
- lead
- sodium
Which of the following structures represents a Lewis structure of sulfate ion?
- A
- B
- C
- D
- E
Which of the following statements is NOT correct?
- The rate of many reactions is affected by the reactant concentration in the solution.
- Exothermic reactions are faster than endothermic reactions.
- Enzymes are very efficient macromolecular biological catalysts.
- Inhibitor is a substance that decreases the rate of a reaction.
- Pressure affects the rate of a reaction involving reacting gases.
The overall number of electrons in the 0.1 mole of sodium ions is:
- 6.022·10²²
- 1.204·10²³
- 6.022·10²³
- 6.624·10²⁴
- 3.011·10²³
According to the following standard reduction potentials, which species is the strongest reducing agent?
E^θ(Zn²⁺/Zn)=-0.76 V
E^θ(Fe²⁺/Fe)=-0.41 V
E^θ(Cu²⁺/Cu)=-0.34 V
- Zn²⁺
- Cu²⁺
- Cu
- Fe
- Zn
Which of the following is the main compound found in human bone and teeth?
- calcium phosphate
- calcium chloride
- calcium oxalate
- calcium carbonate
- calcium fluoride
Which of the following bases is only found in RNA molecule?
- figure 1
- figure 2
- figure 3
- figure 4
- figure 5
Which ion of the listed metals is a part of the oxygen transport system in the human body?
- molybdenum
- iron
- copper
- zinc
- cobalt
Structural formula of lactose is:
- figure 1
- figure 2
- figure 3
- figure 4
- figure 5
The highest freezing point will have the solution prepared by dissolving:
- 0.02 mol of potassium hydroxide in 1 kg of water.
- 0.03 mol of sodium phosphate in 1 kg of water.
- 0.04 mol of ammonium sulfate in 1 kg of water.
- 0.06 mol of hydrogen chloride in 1 kg of water.
- 0.12 mol methanol in 1 kg of water.
Equilibrium processes are NOT _____________
- dissolving reactions of gases in water.
- neutralization reactions.
- ionization reactions of weak acids or weak bases.
- precipitation reactions of slightly soluble salts.
- esterification reactions.
The less abundant element in proteins is:
- N
- C
- H
- O
- S
Which of the following alcohols is a tertiary one?
- glycerol
- 2-methylpropan-2-ol
- ethan-1,2-diol
- 2-bromo-3-ethylpentan-1-ol
- 5,5-dimethylhexan-2-ol
Which of the following elements can be found in nature in free (uncombined) state?
- Al
- Au
- Ba
- Ca
- Si
If 1 mole of 1-butyne reacts with 2 moles of hydrogen bromide the reaction product is:
- 1-bromo-1-butene
- 2-bromo-1-butene
- 1,1-dibromobutane
- 1,2-dibromobutane
- 2,2-dibromobutane
Consider the reaction: CH₃CHO + 2CH₃OH → X + H₂O. The major product (X) of the presented reaction is:
- CH₃CH₂OCH₂CH₃
- CH₃CH(OCH₃)CH₃
- CH₃CH₂CH₂OCH₃
- CH₃CH(OCH₃)₂
- CH₃CH(OH)(OCH₃)
Product of the reaction between benzene and chlorine in the presence of iron(III) chloride as a catalyst is:
- C₆H₆Cl₂
- C₆H₆Cl₆
- C₆H₅Cl
- C₆H₄Cl₂
- C₆Cl₆
Number of chiral atoms in the molecule shown below equals:
- 6
- 5
- 4
- 3
- 2
If the pH of 0.1 M solution of acetic acid is 2.9 at 25°C, it can be concluded that acetic acid:
- dissociates completely in water and is a weak electrolyte.
- dissociates partially in water and is a strong electrolyte.
- is a nonelectrolyte.
- dissociates completely in water and is a strong electrolyte.
- dissociates partially in water and is a weak electrolyte.
Which of the following compounds can NOT form intermolecular hydrogen bonds but can form hydrogen bonds with water molecules?
- alanine
- glucose
- propyl ethanoate
- ethanolamine
- acetic acid
Alkaloid quinine is a medication used to treat malaria. Consider the structure of quinine and find the correct statement.
- The compound is an acid because of the presence of secondary hydroxyl group.
- One ester bond if found within the structure of quinine.
- The quinine is optically inactive molecule.
- The compound is a base because of the presence of tertiary amine group and pyridine.
- Cis/trans stereoisomers of quinine exist.
Which of the following compounds can NOT be subjected to hydrolysis reaction in aqueous media?
- alanyl-glycine
- sucrose
- D-glucose
- adenosine triphosphate
- tripalmitoylglycerol
The INCORRECT statement regarding molecular oxygen is:
- it is flammable.
- it supports combustion.
- one allotropic modification is ozone.
- in dry air, it is present in 21% by volume.
- it is an oxidizing agent.
Vitamin C (C₆H₈O₆) is an essential nutrient for humans. Calculate the mass of carbon, oxygen and hydrogen in a 25.00 mg tablet that contains 91.00% of pure vitamin C. (No other ingredients contain C, H and O.)
- m(C) = 9.31 mg, m(O) = 12.40 mg and m(H) = 1.04 mg
- m(C) = 8.13 mg, m(O) = 14.45 mg and m(H) = 2.42 mg
- m(C) = 1.70 mg, m(O) = 2.27 mg and m(H) = 0.14 mg
- m(C) = 10.23 mg, m(O) = 13.62 mg and m(H) = 1.15 mg
- m(C) = 1.55 mg, m(O) = 2.07 mg and m(H) = 0.13 mg
Which of the following gases has a characteristic smell?
- carbon dioxide
- carbon monoxide
- sulphur dioxide
- oxygen
- hydrogen
Select two isotopes:
- ¹⁶₈X, ³²₁₆Y
- ³¹₁₅X, ³²₁₆Y
- ¹₁X, ²₄Y
- ³²₁₆X, ³⁵₁₆Y
- ³²₁₅X, ³²₁₆Y
Starch and glycogen are both polymers of _______________ and contain (α1 → 4) and (α1 → 6) _____________ bonds.
- glucose; anhydride
- glucose and fructose; amide
- glucose; glycosidic
- glucose; peptide
- galactose; glycosidic
For the presented peptide it is NOT correct:
- The peptide is a tetrapeptide.
- N-terminal amino acid is cysteine.
- C-terminal amino acid is glycine.
- The peptide molecule isn't amphoteric.
- Three water molecules are required for the hydrolysis of amide bonds present in the peptide molecule.