Get premium membership and access revision papers, questions with answers as well as video lessons.
Sch2107:Inorganic Chemistry Question Paper
Sch2107:Inorganic Chemistry
Course:Bachelor Of Horticulture
Institution: Meru University Of Science And Technology question papers
Exam Year:2013
You may find the following information useful
? ?????????????????? ???????????????? ???? = 6.023 × 1023??????-1 ? ???????????? ????????????????,?? = 6.626 × 10-34???? ? ?????????? ???? ??????????,?? = 2.998 × 108??/?? ????47107 .87 ???? ???? ?? ?? 7 14.01 1 1.008 26 55.85 11 22.99 ???? ???? ???? ?? ???? ???? ?? ?? 6 12.01 1632 .06 28 58.71 20 40.08 8 16.00 29 63.54 24 52 18 39.95
QUESTION ONE (30 MARKS)
a) i) What are the requirements of a primary standard? (2 ½ Marks) ii) 21.2g of AgNO3 is dissolved in enough distilled water to make 250ml of solution. What is the molarity of this solution? (2 Marks) b) Differentiate between: i. Precision of measurement and accuracy of measurement. (1 Mark) ii. Random error and systematic error. (1 Mark) iii. Extensive measurements and intensive measurements. (1 Mark) iv. Base units and derived units. (1 Mark) c) i) Rank the various regions of the electromagnetic spectrum in order of increasing wavelength. (1 Mark) ii) What is the energy per mole (in kJmol-1) of photons of wavelength, 514nm emitted in the Ar+ transition which is exploited to make laser light. (2 ½ Marks)
2
d) i) Within each period of the periodic table, the atomic radius decreases with increasing atomic number. Explain. (2 Marks) ii) Arrange the isoelectronic species ??-3,??-2,????,????2+ ?????? ????+4 in order of increasing size. Give reason for selecting this order. (2 Marks) e) i) complete the following nuclear reactions ???? 11 23 + ?? 1 2 ? ?? + ?? 1 1 (1 Mark) ??92 238 + ?? 7 14 ? ?? + 6 ?? 0 1 (1 Mark)
ii) Summarize the major characteristics of nuclei for which we predict a high degree of stability. (4 Marks) f) i) State the Pauli’s exclusion principle. (1 Mark) ii) Account for the decrease in the first ionization energy between N and O. (3 Marks) iii) Give the ground state electron configuration of ????,????2+,???? ?????? ????3+. (4 Marks)
QUESTION TWO (20 MARKS)
a) i) A simple example of covalent compound is the hydrogen molecule. Illustrate the overlap of the 1s orbitals in the diatomic hydrogen molecule. (2 Marks) ii) Predict whether each of the following molecules is polar or non-polar. In each case give reasons. i. CO2 ii. BCl3 iii. NH3 iv. HCl v. SiCl4 b) i) Draw a Born – Haber cycle for the formation of Calcium hydride. (5 Marks) ii) Show how the electron affinity of the hydrogen atom is obtained. (1 Mark) c) i) What is meant by the term enthalpy? (2 Marks) ii) Why an exothermic reaction gives products that are more than the reactants. (2 Marks) d) Sketch a set of the p-orbitals on separate axes. (3 Marks)
QUESTION THREE (20 MARKS)
a) i) A 6.00ml portion of 0.400M stock solution is diluted to 8.00ml. What will be the final concentration after dilution? (2 Marks) ii) A 0.4671g sample containing sodium bicarbonate was dissolved and titrated with a solution of hydrochloric acid, requiring 40.72ml. The hydrochloric acid was standardized by titrating 0.1876g sodium carbonate and the titration required 37.86ml acid. Calculate the percent of sodium bicarbonate in the sample. (6 Marks) b) i) A 100.00mg sample of sodium – 24 was stored in a lead – lined cabinet for 2.5days. How much sodium – 24 remained given that its half-life is 15 hour? (2 Marks) ii) What is the mass defect for arsenic if the isotopic mass is 74.9216(amu)? (3 Marks)
3
iii) What is meant by the following terms?
(i) Nuclear fission (ii) Relative biological effect. (3 Marks) c) Draw the Lewis dot structure for each of the following ions: i. ????4 2- ii. ????3 - (4 Marks)
QUESTION FOUR (20 MARKS)
a) i) Define the terms theoretical yield and percentage yield, and explain why the later may be less than 100%. (4 Marks) ii) Nitrogen dioxide contributes to the formation of acid rain as a result of its reaction with water in the air, according to the reaction; 3NO2 (g) + H2O (g) 2HNO3 (aq) + NO (g) What mass (in milligrams) of HNO3 can be produced from the reaction of 2.93mg of NO2, assuming an excess of H2O? If only 1.91mg of HNO3 was produced in the reaction, what is the percentage yield? (4 Marks) iii) The souring of wine occurs when ethanol, C2H5OH is connected by oxidation into acetic acid; C2H5OH (aq)+ O2(g) CH3COOH(aq) + H2O(l) If 2.00g of ethanol and 1.00g of oxygen were sealed in a wine bottle, which would be the limiting reactant for the oxidation? (3 Marks) b) A folk medicine used in one of the provinces in China to treat acute dysentery in Cha-tiao – qi. Reacting one of the active ingredient in cha-tiao-qi with water yields gallic acid, a powerful antidysentric agent. Gallic acid is known to contain carbon, hydrogen and oxygen. A chemist wanting to determine the molecular formula of gallic acid performed a combustion analysis of 1.000g of the compound. The products of the combustion were 1.811g of CO2 and 0.3172g of H2O. i. Assuming that all the carbon atoms in the CO2 came from the sample of gallic acid, what was the mass of carbon in the sample? (1 ½ Marks) ii. Assuming that all the hydrogen atoms in the H2O came from the sample, what was the mass of hydrogen in the sample? (1 ½ Marks) iii. Use the information from (i) and (ii) to determine how many grams of oxygen were present in the sample and calculate the mass percentage composition of the compound. (2 Marks) iv. Determine the empirical formula of the compound. (2 Marks). v. If molecular mass of gallic acid is 170.12g/mol, what is the molecular formula of gallic acid? (2 Marks)
More Question Papers
Popular Exams
Return to Question Papers