hey ppl... how's the maths and science exam earlier on??? looks like my tips are spot on ya??? anywae... jus some clarity... jus some answers that shud be correct =)
theres one question on breaking down of copper... its found inside ur prac book. answer : 2.
Thermal Decomposition
copper(II) carbonate --> copper(II) oxide + carbon dioxide
CuCO3 --> CuO + CO2
another is on electrolysis if im not wrong. observation 1 = red brownish solid formed on iron nail. observation 2 = copper coin dissolves. explanation = copper (ii) ions gain electrons from teh solution, forming copper atoms. these atoms are then deposited on the iron nail thus the reddish bown solid, which is copper, is formed.
another one, When dissolved with acid, magnesium carbonate decomposes with release of carbon dioxide:
MgCO3 + HCl → MgCl2 + CO2 + H2O
In the Dow process, magnesium chloride is regenerated from magnesium hydroxide using hydrochloric acid:
Mg(OH)2(s) + 2 HCl → MgCl2(aq) + 2 H2O(l)
*magnesium hydroxide = milk of magnesium
ok.. thats all i rmb... good luck for the other 2 exams!
2 DAYS TO MERDAKA
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