Chemistry Past Questions And Answers

Note: You Can Select Post UTME Schools Name Below The Exam Year.
261

Four elements P, Q, R and S have 1, 2, 3, and 7 electrons in their outermost shells, respectively. The element which is likely to be a metal is

  • A) P
  • B) Q
  • C) R
  • D) S
View Discussion (0)POST UTME FUTO
262

What is the relative molecular mass of the compound below?

[H = 1.0; C = 12.0; O = 16.0]

  • A. 137
  • B. 136
  • C. 64
  • D. 59
View Discussion (0)WAEC 2021 OBJ
263

A measure of the degree of disorder in a chemical system is known as the

  • A. enthalpy
  • B. free energy
  • C. activation energy
  • D. entrophy
View Discussion (0)WAEC 1994 OBJ
264

(a) Write the molecular formula of X.

(i) What type of reaction is represented by the equation?

(ii) Consider the following reaction equation: C\(_{12}H_2\) \(\to\) X + C\(_8\)H\(_{18}\)

(iii) Draw the structure of two isomers of X.

(iv) Name the isomers drawn in (a)(iii).

(v) Write a balanced equation for the reaction between X and hydrogen.

(b) Describe one test for fats.

(c) Sulphur (IV) oxide is converted to tetraoxosulphate (VI) acid according to the following equation: 2SO\(_{2(g)}\) + O\(_{2(g)}\) + 2H\(_2\)O\(_{(l)}\) \(\to\) 2H\(_2\)OSO\(_{4(aq)}\). If 1.5 moles of oxgen reacts with sulphur (IV) oxide, calculate the mass of tetraoxosulphate (VI) acid produced. [H = 1.0; O = 16.0; S = 32.0].

(d) Consider the following neutralization reaction:

CH\(_3\)COOH + NaOH \(\to\) CH\(_3\)COONa + H\(_2\)O; \(\bigtriangleup\)H\(_1\)

CH\(_3\)COOH + NH\(_4\)OH \(\to\) CH\(_3\)COONH\(_4\) + H\(_2\)O; \(\bigtriangleup\)H\(_2\)

NaOH + HCl \(\to\) NaCl + H\(_2\)O \(\bigtriangleup\)H\(_3\)

(i) Arrange the enthalphy changes for the reactions in order of increasing magnitude.

(ii) Explain briefly your order in (d)(i).

(e) Consider the following substances. Cu\(_{(s)}\), BeCl\(_2\), NaH\(_{(s)}\), HF\(_{(s)}\)and CCl\(_{4(l)}\). State the substance(s) which;

(i) can conduct electricity;

(ii) is/are soluble in water.

View Discussion (0)WAEC 2017 THEORY
265

The following gases decolorize bromine water except

  • A. C2H6
  • B. C2H4
  • C. C2H2
  • D. C3H4
View Discussion (0)WAEC 1993 OBJ
266

which of the following metals will show the highest metallic character?

  • A) Zinc
  • B) Copper
  • C) Barium
  • D) Calcium
View Discussion (0)JAMB 2009
267

Which of the following statements about dative bonding is not correct?

  • A. there is sharing of electrons
  • B. one atom must possess a lone pair electrons
  • C. each participating atom contributes one electron
  • D. it can be formed between molecules
View Discussion (0)WAEC 2003 OBJ
268

Which of the following arrangements is in order of increasing ionization energy?

  • A. AI, Si, P, S
  • B. Si, AI,S,P
  • C. S,P,Si,AI
  • D. P, Si,S,AI
View Discussion (0)WAEC 2009 OBJ
269

Soap lather is an example of a colloid in which a?

  • A. liquid is dispersed in gas
  • B. solid is dispersed in liquid
  • C. gas is dispersed in liquid
  • D. liquid is despersed in liquid
View Discussion (0)JAMB 1998
270

Which of these is correct about methyl orange?

  • A) Yellow in excess aqueous hydrogen ions
  • B) Pink in excess aqueous hydrogen ions
  • C) Orange in excess aqueous hydrogen ions
  • D) Colourless in excess aqueous hydrogen ions
View Discussion (0)POST UTME OAU