Tutorial 2: General Chemistry Past Paper PDF

Tutorial 2 General Chemistry CH4001/CH4701 1. An isotope of the element uranium has a mass number of 235 and an atomic number of 92. What are the number of electrons, protons, and neutrons, respectively, in a neutral atom of this isotope? quetsions like this...

Tutorial 2 General Chemistry CH4001/CH4701 1. An isotope of the element uranium has a mass number of 235 and an atomic number of 92. What are the number of electrons, protons, and neutrons, respectively, in a neutral atom of this isotope? quetsions like this one at end of year exam 20 20 2. 10Ne, 9 F, and 20 11Na all have from past exam paper Electrons = Protons in Neutral atoms a) 20 protons. b) 20 neutrons. c) a mass number of 20. d) 20 electrons. e) 11 neutrons. 3. Which of the following statements is true for neutral atoms? a) It is possible for neutral atoms of different elements to have the same number of electrons. b) The number of neutrons in a neutral atom must always equal the number of protons. c) It is possible for neutral atoms of different elements to have the same number of neutrons. d) It is possible for neutral atoms of different elements to have the same number of protons. 4. The molar mass of gallium atoms in a natural sample is 69.72 g mol–1. The sample consists of Ga-69 of molar mass 68.9256 g mol–1 and Ga-71 of molar mass 70.9247 g mol–1. What are the percentage abundances of these two isotopes? (sotope AM 1 x % Abund) + (Isotope AM 2 x % Abund) /100 5. Naturally occurring rubidium consists of two isotopes, one of which has an atomic mass of 86.92 a.m.u. and a natural abundance of 27.86%. If the observed chemical atomic mass of rubidium is 85.47, calculate the atomic mass of the other isotope. same formula as Q4. 6. Which of the following is an empirical formula? Empirical formula: the relative number of atoms of a) S2O4 SO2 / emperical formula for a) each element in a molecule or formula unit b) Pb2O4 emp. formula for B) PbO2 c) C2H4O2 emp.formula for C) CH2O d) CH2O e) N2H4 emp. formula for E) NH2 7. In the following list which is NOT an example of a chemical reaction. (a) dissolution of a cent coin in nitric acid (b) the condensation of water vapour (c) the burning of a candle (d) the rusting of iron (e) the mixing of HCl and NaOH 8. Express the temperature, 422.35 K, in degrees Celsius watch out you need to substract the diffrence / 1 celsius = 271 kelvin/ (a) 792.23°C 422.35-271=149.20 (b) 149.20°C (c) 695.50°C (d) 50.89°C (e) 22.78°C 9. Which of the following has 18 neutrons and 18 electrons? (a) (a) 40Ar (Z=18) (b) (b) 35Cl− (Z=17) (c) (c) 32S2− (Z=16) (d) (d) 31P3− (Z=15) (e) (e) 28Si (Z=14) 10. Which of the following species has 48 electrons? 118 (a) 50 Sn2+ 116 (b) 50 Sn4+ 112 (c) 48 Cd2+ 68 (d) 31 Ga 48 (e) 22 Ti