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36 Lactic acid produced by bacteria can cause sour taste in milk. It has similar empirical
formula with ethanoic acid.
Two molecules of lactic acid have the same mass as three molecules of ethanoic acid.
What is the molecular formula of lactic acid?
[Relative atomic mass: C = 12, H =1, O =16]

Asid laktik yang dihasilkan oleh bakteria boleh menyebabkan susu berasa masam.
Formula empirik asid laktik dan asid etanoik adalah sama.
Dua molekul asid laktik mempunyai jisim yang sama dengan tiga molekul asid
etanoik.
Apakah formula molekul asid laktik.
[Jisim atom relatif : C= 12, H =1, O = 16]

A C 3H 6O 3 C CH 2O
B C 2H 4O 2 D C 4H 12O 4

37 Which of the following equations can produce fruit flavouring?
Antara persamaan berikut, yang manakah boleh menghasilkan perisa buah-buahan?
I CH 3COOH + NaOH  CH 3COONa + H 2O
II C 2H 5OH + C 2H 5COOH  C 2H 5COOC 2H 5 + H 2O
III C 3H 7OH + 2[O]  C 2H 5COOH + H 2O
IV C 8H 17OH + CH 3COOH  CH 3COOC 8H 17 + H 2O

A I and III only C III and IV only
I dan III sahaja III dan IV sahaja
B II and IV only D I, II and IV only
II dan IV sahaja I, II dan IV sahaja

38 Which metal can prevent rusting when it is in contact with iron?
Logam manakah yang dapat mencegah pengaratan apabila bersentuh dengan besi?
A Lead C Copper
Plumbum Kuprum
B Silver D Magnesium
Argentum Magnesium

39 The chemical equation for the reaction to produce oxygen is as follows:
Persamaan kimia bagi tindak balas penghasilan gas oksigen adalah seperti berikut:

2 KClO 2 KCl + 3 O 2
3

What is the change in oxidation number of chlorine? Apakah perubahan nombor
pengoksidaan bagi klorin ?

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