Question Library — KalmiPrep by Kalmitech

Chemistry WAEC / WASSCE 2008 Water, Solutions & Solubility

(a)(i) Define hard water (ii) Name two substances responsible for hardness in water (iii) Give two methods for the removal of hardness in water. (b)(i) What are the raw materials require for the manufacture of tetraoxosulphate (VI) acid by the contact process? (ii) Write an equation for tr reaction that requires a catalyst in the contact process (iii) State the catalyst used in (b)(ii). (c)(i) Give two uses of sodium tetraoxosulphate (VI) Consider the reaction represented by the following equation: Na\(_2\)SO\(_4\).10H\(_2\)O\(_{(s)}\) \(\to\) Na\(_2\)SO\(_4\).H\(_2\)O + 9H\(_2\)O\(_{(g)}\) (ii) What name is given to this type of reaction? (iii) Calculate the solubility of Na\(_2\)CO\(_3\) at 25^\circC. if 30.0 cm\(^3\) of its saturated solution at that temperature gave 1.80 g of the anhydrous salt. [C = 12, 0 = 16, Na = 23] (d)(i) Define the term activated complex (ii) State one reason why a collision may not produce a chemical reaction (iii) The formation of water gas is represented by the following equation: C\(_{(s)}\) + H\(_2\)O\(_{(g)}\) \(\to\) CO\(_{(g)}\) + H\(_{2(0)}\) \(\Delta\)H= + 131 kJmol\(^{-1}\) Draw an energy profile diagram for the reaction showing the I. activated complex, II. enthalpy of reactants.

medium Difficulty

English Language WAEC / WASSCE 2008 Lexis, Structure & Register (Cloze & Vocabulary)

In question numbered 99 above, choose the best option from letters A - D that best completes the gap.

A

struggled

B

grumbled

C

suffered

D

toiled

medium Difficulty

English Language WAEC / WASSCE 2008 Lexis, Structure & Register (Cloze & Vocabulary)

In question numbered 100 above, choose the best option from letters A - D that best completes the gap.

A

roof

B

structure

C

wall

D

apartment

medium Difficulty

Chemistry NECO SSCE 2008 Reaction Rates & Chemical Equilibrium

In which of the following equations can Le-chartelier’s principle be applied?

A

H2(g)+S(g) → H2(g)

B

2H2S(g) + O2 (g) → 2H2O(l) + 2SO2(g)

C

N2(g) +3H2(g) ⇌ 2NH3(g)

D

NaOH(aq) +CO2(g) → Na2CO3(aq) + H2O(l)

E

S(s) + 02(g) → SO2(g)

medium Difficulty

Chemistry WAEC / WASSCE 2008 Organic Chemistry II: Functional Groups, Polymers & Biomolecules

(a) In the laboratory preparation of crystals of CuSO\(_4\), a green powder Q was added to dilute H\(_2\)SO\(_4\), and stirred. Effervescence occurred and a gas R was given off which turned lime water milky. Excess Q was removed from the mixture. The solution of Cu\(_2\)SO\(_4\) was concentrated to half its original volume and allowed to stand. (i) What is substance Q? (ii) Name gas R (ii) Why was excess Q used? (iv) How would you know that the reaction is complete? (v) What method was used to remove excess Q? (vi) Why was the solution of CusO\(_4\) not heated to dryness? (b) Name the reagent(s) used for testing each of the following substances in the laboratory: (i) Water; (i) Primary alkanol.

medium Difficulty

Chemistry WAEC / WASSCE 2008 Nature of Matter & Separation Techniques

Credit will be given for strict adherence to the instructions, for observations precisely recorded, and for accurate inferences. All tests, observations, and inferences must be clearly centered in your answer book, at the time they are made. C is a mixture of two salts. Carry outline following exercises on C. Record your observations and identify any gas(es) evolved. State the conclusion you draw from the result of each test. (a) Put C into a beaker and add about 10 cm\(^3\) of distilled water, stir the mixture, and filter. Test the filtrate with litmus paper. Keep the residue and the filtrate. (b)(i) To about 2 cm\(^3\) of the filtrate, add few drops of aqueous HNO\(_3\) followed by AgNO\(_{3(aq)}\) (ii) Add excess NH\(_3\) solution to the resulting mixture. (c) To about half of the residue from (a) above, add about 5cm\(^3\) of dilute HNO\(_3\) in drops. Divide the resulting solution into two equal portions. (d)(i) To the first portion add ammonia solution in drops and then in excess. (ii) To the second portion add dilute hydrochloric acid.

medium Difficulty

Chemistry WAEC / WASSCE 2008 Stoichiometry, Mole Concept & Volumetric Analysis

Burette readings(initial and final) must be given to two decimal places. Volume of pipette user must also be recorded but on account of experimental procedure is required. All calculations must be done in your answer book. A is O.050 mol dm\(^{-3}\) of acid HX. Bis a solution of NaOH containing 0.025 moles per 250 solutions. (a) Put A into the burette and titrate it against 20.00 cm\(^3\) or 25.00 cm\(^3\) portions B using phenolphthalein as indicator. Tabulate your readings and calculate the average volume or A used. (b) your results and the information provided above, calculate the; (i) amount of acid in the average (ii) amount of base in 20.00 cm\(^3\) or 25.00 cm\(^3\); (iii) mole ratio of acid to base (c) Write a balanced chemical equation for the reaction between the acid H\(_y\)X and the base NaOH (d) State the basicity of the acid H\(_y\)X.

medium Difficulty

English Language UTME / JAMB 2008 Lexis, Structure & Register (Cloze & Vocabulary)

In question number 25 above choose the best option from letters A- D that best complete the gap

A

rational

B

reactional

C

proactive

D

radical

medium Difficulty

English Language NECO SSCE 2008 Oral English: Vowel & Consonant Sounds

Choose from the options lettered A - E the one that contains the sound segment represented by the given phonetic symbol /\theta/

A

tank

B

teethe

C

thank

D

they

E

this

medium Difficulty

English Language NECO SSCE 2008 Oral English: Vowel & Consonant Sounds

Choose from the options lettered A - E the one that has the same vowel sound as the one represented by the underlined Letter(s). gear

A

badge

B

bridge

C

jeer

D

large

E

leg

medium Difficulty

English Language NECO SSCE 2008 Oral English: Vowel & Consonant Sounds

Choose from the options lettered A - E the one that has the same vowel sound as the one represented by the underlined letter(s) may

A

car

B

man

C

mark

D

mean

E

shake

medium Difficulty

English Language NECO SSCE 2008 Synonyms (Nearest in Meaning)

Choose from the options lettered A - E the one that is nearest in meaning to the word underlined. My principal gives his candid opinion on every issue brought before him.

A

complete

B

fatherly

C

frank

D

honest

E

vague

medium Difficulty

English Language NECO SSCE 2008 Oral English: Stress, Rhymes & Intonation

Choose from the options lettered A - E the one that has the same stress with the word given. In each word, only one syllable has the main/primary and the syllable is written in capital letters desegregate

A

DE-seg-re-gate

B

de-SEG-re-gate

C

de-seg-RE-gate

D

de-seg-re-GATE

E

DE-seg-re-GATE

medium Difficulty

English Language NECO SSCE 2008 Lexis, Structure & Register (Cloze & Vocabulary)

Choose from the options lettered A - E the one that most appropriately completes each sentence Olu has returned the pencil he________him.

A

handed

B

borrowed

C

dashed

D

lent

E

given

medium Difficulty

English Language NECO SSCE 2008 Oral English: Vowel & Consonant Sounds

Choose from the options lettered A - E the one that has the same consonant sound as the one represented by the underlined Letter(s). thin

A

bathe

B

day

C

there

D

they

E

tooth

medium Difficulty