化學不明高手解答

Which of the following compounds does not form a solidoxide when heated strongly?
A:copper(II)sulphate
B:lead(II)carbonate
C:potassium nitrate
D:calcium hydroxide


The answer is: C: potassium nitrate
(I think you have gotten a wrong answer. The answer is C but NOT B.)

A: A solid oxide is formed.
Copper(II) sulphate decomposes on heating to give copper(II) oxide solid andsulphur trioxide gas.
CuSO4(s) → CuO(s) + SO3(g)

B: A solid oxide is formed.
Lead(II) carbonate decomposes on heating to give lead(II) oxide solid andcarbon dioxide gas.
PbCO3(s) → PbO(s) + CO2

C: No solid oxide is formed.
Potassium nitrate decomposes on heating to give potassium nitrite solid andoxygen gas.
2KNO3(s) → KNO2(s) + O2(g)

D: A solid oxide is formed.
Calcium hydroxide decomposes on heating to give calcium oxide solid and watervapour.
Ca(OH)2(s) → CaO(s) + H2O(g)

同意老爺子的說法.
用常理推斷: CaCO3 (強烈)加熱已經可以分解, 而CaO 是一種比PbO 帶更強鹼性的物質, 即是說PbCO3 本身比CaCO3 更不穩定, 更容易分解.

For A, when heated strongly, copper(II) sulphate (anhydrous) decomposes to form copper(II) oxide and produce a sulphur trioxide gas.
CuSO4 (s) -> CuO (s) + SO3 (g)For B, when heated strongly, no reaction occurs.For C, when heated strongly, potassium nitrate decomposes to form potassium nitrite and produce an oxygen gas.
2KNO3 (s) -> 2KNO2 (g) + O2 (g)For D, when heated strongly, calcium hydrogen decomposes to form calcium oxide and water.
Ca(OH)2 (s) -> CaO (s) + H2O (g)


2011-05-30 19:03:06 補充：
sorry... 沒注意到solid oxide這字眼...
他們的答案均是正確