Che0100:Chemistry. Question Paper
Che0100:Chemistry.
Course:Diploma In Agriculture
Institution: Meru University Of Science And Technology question papers
Exam Year:2012
QUESTION ONE – (30 MARKS)
a) Differentiate between i. Chemical and physical properties (2 Marks) ii. Extensive and intensive properties. (2 Marks) b) State the law of definite proportions. (2 Marks) c) How many atoms are present in 47.66g of copper? [Cu=63.55], [NA=6.02 × 1023] (4 Marks) d) Show the electronic structures of the following elements whose atomic numbers are shown in (i) (iii) below i. 16 (2 Marks) ii. 7 (2 Marks) iii. 25 (2 Marks) e) Given that the subsidiary (azimuthal) quantum numbers l for an element is 1. Determine i. The principal quantum number, n (2 Marks) ii. The magnetic quantum number, m (2 Marks) f) Ammonia is formed by the reaction between hydrogen and nitrogen as shown in the equation below N2 (g) + 3H2(g) 2NH3(g)
i. How many moles of hydrogen will be required to produce 1 mole of ammonia? (2 Marks) ii. How many tons of nitrogen will be required to produce 5 tons of ammonia? (2 Marks)
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g) Draw the molecular structures of i. 2, 3 dimethylbutane. (2 Marks) ii. 3 methylhexane. (2 Marks) iii. 2 pentene (2 Marks)
QUESTION TWO (15 MARKS)
a) Sulpur dioxide reacts with oxygen as shown 2SO2(g) +O2(g) 2SO3(g) i. Write the expression for the equilibrium constant Kc for this reaction. (2 Marks) ii. How will the position of equilibrium be affected if sulphur dioxide is removed from the reaction mixture. Explain your answer? (4 Marks) b) Nitric oxide NO, reacts with oxygen O2, at 2700C and establishes an equilibrium as shown; 2NO(g) + O2(g) 2NO2(g)
If at equilibrium the concentration of the reacting species were found to be; [NO] = 2.7 × 10-3??, [O2] = 0.127 and [NO2] =0.775M. Calculate the equilibrium constant Kc at 2300C. (4 Marks)
c) tate e hatelier’s principle (2 Marks) d) Consider the following equilibrium system SO2(g) +Cl2(g) SO2Cl2(g) How would the equilibrium change if;- i. Cl2 was removed from the system? (1 ½ Marks) ii. SO2 was added to the system? (1 ½ Marks)
QUESTION THREE (15 MARKS)
a) What are isotopes? Explain your answer with relevant examples. (2 Marks) b) A certain oxide of nitrogen is found to contain 2.34g of N and 5.34g of O. Determine the empirical formula of the oxide. [N=14, O=16]. (6 Marks) c) Beryllium metal differs in its reaction from the rest of the group IIA metals but shows diagonal relationship with aluminium in group IIIA. In what ways does beryllium show similarities with aluminium? (7 Marks)
QUESTION FOUR (15 MARKS)
a) In which functional group does each of the following compounds belong? (5 Marks)
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i. C4H10 ii. C4H8 iii. C4H6 iv. C4H9OH v. C3H6COOH b) An hydrocarbon contains carbon and hydrogen only. Its molecular formula is C5H12. (6 Marks) c) What factors are unique with carbon atom that enable it to form stable covalent compounds such as the hydrocarbons? (4 Marks)
QUESTION FIVE (15 MARKS)
a) Explain why; i. The atomic radii of the gases in group VIII (the noble gases) are the smallest among the elements in any period. (3 Marks) ii. The halogens group VIIA is typically non-metallic in character while the alkali metals (group IA) have typical metallic character. (3 Marks) iii. Potassium (Z = 19) ionizes easily while argon (Z = 18) is very difficult ionize. (4 Marks) b) i) Name three types of bonding as found in chemical substances. (3 Marks) ii) Show the Lewis symbol for the nitrogen molecule, N2 given that N=7. (2 Marks)
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