Pregunta 1
Pregunta
1. On analysis, a compound with molar mass 60 gmol-1 was found to contain 12g of carbon, 2g of hydrogen and 16 g of oxygen. What is the molecular formula for the compound?
Respuesta
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A. CH2O
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B. CH4O
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C. C2H4O
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D. C2H4O2
Pregunta 2
Pregunta
2. 300 cm3 of water are added to a solution of 200 cm3 of 0.5 moldm-3 sodium chloride. What is the concentration of sodium chloride in the new solution?
Respuesta
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A. 0.05 moldm-3
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B. 0.1 moldm-3
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C. 0.2 moldm-3
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D. 0.3 moldm-3
Pregunta 3
Pregunta
3. Which statement about the species 63Cu2+ and 65Cu+ is correct?
Respuesta
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A. Both species have the same number of protons.
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B. Both species have the same number of electrons.
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C. Both species have the same number of neutrons.
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D. Both species have the same electron arrangement.
Pregunta 4
Pregunta
4. Which statements about the periodic table are correct?
I. The elements Mg, Ca and Sr have similar chemical properties.
II. Elements in the same period have the same number of main energy levels.
III. The oxides of Na, Mg and P are basic.
Respuesta
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A. I and II only.
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B. I and III only.
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C. II and III only.
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D. I, II, and III
Pregunta 5
Pregunta
5. In which complexes does iron have an oxidation number of +3?
I. [Fe(H2O)6]3+
II. [Fe(H2O)5(CN)]2+
III. [Fe(CN)6]3-
Respuesta
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A. I and II only.
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B. I and III only.
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C. II and III only.
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D. I, II and III.
Pregunta 6
Pregunta
6. Which species contain a dative covalent bond?
I. HCHO
II. CO
III. H3O+
Respuesta
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A. I and II only.
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B. I and III only.
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C. II and III only.
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D. I, II and III
Pregunta 7
Pregunta
7. Which substance is made up of a lattice of positive ions and free-moving electrons?
Respuesta
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A. Graphite
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B. Sodium chloride
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C. Sulfur
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D. Sodium
Pregunta 8
Pregunta
8. Which species have delocalized electrons?
I. (CO3)2-
II. O3
III. HCOOH
Respuesta
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A. I and II only
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B. I and III only
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C. II and III only
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D. I, II and III
Pregunta 9
Pregunta
9. Identical pieces of magnesium are added to two beakers, A and B, containing hydrochloric acid. Both acids have the same initial temperature but their volumes and concentrations differ.
A - 100cm3 of 1.0moldm-3 HCl
B - 200cm3 of 0.50moldm-3 HCl
Which statement is correct?
Respuesta
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A. The maximum temperature in A will be higher than in B.
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B. The maximum temperature in A and B will be equal.
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C. It is not possible to predict whether A or B will have the higher maximum temperature.
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D. The temperature in A and B will increase at the same rate.
Pregunta 10
Pregunta
10. Which is a correct definition of lattice enthalpy?
Respuesta
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A. It is the enthalpy change that occurs when an electron is removed from 1 mol of gaseous atoms.
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B. It is the enthalpy change that occurs when 1 mol of a compound is formed from its elements.
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C. It is the enthalpy change that occurs when 1 mol of solid crystal changes into a liquid.
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D. It is the enthalpy change that occurs when 1 mol of solid crystal is formed from its gaseous ions.
Pregunta 11
Pregunta
12. Which molecule has an octahedral shape?
Respuesta
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A. SF6
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B. PCl5
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C. XeF4
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D. BF3
Pregunta 12
Pregunta
11. Calcium carbonate decomposes on heating as shown below:
CaCO3 --> CaO + CO2
When 50 g of calcium carbonate are decomposed, 7 g of calcium oxide are formed. What is the percentage yield of calcium oxide?
Respuesta
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A. 7%
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B. 25%
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C. 50%
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D. 75%
Pregunta 13
Pregunta
13. Which compound dissolved in water to form a solution that does NOT conduct electricity?
Respuesta
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A. HCl
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B. NaCl
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C. CH3CH2OH
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D. CH3COOH
Pregunta 14
Pregunta
14. What intermolecular forces are present in gaseous hydrogen?
Pregunta 15
Pregunta
15. What is the shape of the species ICl4-?
Respuesta
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A. Pyramidal
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B. Square Planar
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C. Tetrahedral
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D. Octahedral
Pregunta 16
Pregunta
16. Which are characteristics of ions in ionic compound with a large lattice enthalpy value?
Respuesta
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A. Large ionic radius and high ionic charge.
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B. Small ionic radius and low ionic charge.
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C. Large ionic radius and low ionic charge.
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D. Small ionic radius and high ionic charge.
Pregunta 17
Pregunta
17. Which species reacts most readily with propane?
Respuesta
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A. Br2
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B. Br•
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C. Br-
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D. Br+
Pregunta 18
Pregunta
18. Which species is a free radical?
Respuesta
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A. •CH3
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B. +CH3
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C. -CH3
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D. :CH3
Pregunta 19
Pregunta
19. Which pair of compounds can be used to prepare CH3COOCH3?
Respuesta
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A. Ethanol and methanoic acid
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B. Methanol and ethanoic acid
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C. Ethanol and ethanoic acid.
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D. Methanol and methanoic acid
Pregunta 20
Pregunta
20. Which can be made in one step from a primary alcohol?
I. An aldehyde.
II. An alkene
III. A ketone
Respuesta
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A. I and II only
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B. I and III only
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C. II and III only
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D. I, II and III
Pregunta 21
Pregunta
21. Which process can produce a polyester?
Respuesta
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A. Addition polymerization of a dicarboxylic acid.
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B. Condensation polymerization of a diol and a dicarboxylic acid.
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C. Addition polymerization of a diol and dicarboxylic acid.
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D. Condensation polymerization of a dicarboxylic acid.
Pregunta 22
Pregunta
22. Which statement about stereoisomers is correct?
Respuesta
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A. 1,2-dichloroethane has two geometrical isomers.
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B. 1,2-dichloroethane has two optical isomers.
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C. 1,2-dichloroethene has two geometrical isomers.
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D. 1,2-dichloroethene has two optical isomers.