VJC Prelim P1_Questions_Answers

For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Use of Data Booklet is relevant to this question. In an experiment, a sample containing 2 different species was vaporised, ionised and passed through an electric field. Analysis of the deflection occurring at the electric region revealed the following data for the sample. It was observed that a beam of 24Mg2+ gives an angle of deflection of +4.0 °. Which one of the following species will give the correct angle of deflection? isotope no. of electrons angle of deflection A 16O 6 –6.0 º B 23Na 10 +2.1 º C 28Si 10 –6.9 º D 35Cl 18 +1.4 º 2 Which one of the following corresponds to the electronic configuration of the 6 outermost electrons of a Group 6 element in its ground state? A 3d4 4s2 B 3d5 4s1 C 4s2 4p4 D 4p6 3 Which of the following have species arranged in increasing bond angle about the central atom? 1 ICl4– IO3–, I3– 2 XeF4, XeO3, XeF2 3 N2O, NO3–, NO2+ 4 SO42–, SO32–, SO2 A 1 and 2 only C 1, 3 and 4 only B 1, 2 and 4 only D 2 and 3 only +4.0 º - + 24Mg2+ Source

4 The molar mass of ethanoic acid is 120.0 g mol–1 when dissolved in trichloromethane but 60.0 g mol–1 when dissolved in water. Which one of the following statements best explains the phenomenon? A Ethanoic acid is more soluble in trichloromethane than in water. B Ethanoic acid molecules form strong covalent bonds with trichloromethane molecules. C Ethanoic acid evaporates more readily in water. D Ethanoic acid molecules form extensive hydrogen bonds with water molecules. 5 1.00 mol of gaseous molecules of a compound A, takes up a volume of 39 dm 3 when subjected to a pressure of 1.52 atm at a temperature of 70 ºC. Which of the following statements explain the above observation? 1 Gaseous molecules of A experiences strong intermolecular forces of attractions. 2 Gaseous molecules of A have a significant molecular volume. 3 Gaseous molecules of A are in constant, rapid, random motion. A 1, 2 and 3 C 2 and 3 only B 1 and 2 only D 1 only 6 P, Q and R are 3 consecutive elements in Period 3 of the Periodic Table.  R has the highest melting point out of the 3 elements.  The chloride of P gives a solution that is least acidic in water as compared to chlorides of Q and R.  The 3rd ionisation energy of Q is much lower than that of P. What can P, Q and R be? A Na, Mg, Al C Al, Si, P B Mg, Al, Si D Si, P, S 7 Which one of the following statement s about Group 2 elements and their compounds is correct? A Calcium hydroxide has a higher solubility than magnesium hydroxide. B Calcium reacts with barium chloride to give calcium chloride. C Strontium carbonate, on heating over a short period of time, decomposes to give more carbon dioxide gas than magnesium carbonate. D Magnesium has a lower melting point than strontiu