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Topic: 2005 A Level questions for me  (Read 3533 times)

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HongKongALevelboy

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2005 A Level questions for me
« on: April 20, 2005, 05:03:21 AM »
hi , i just took my Hong Kong A Level exam on 4/19
i have a question on it

Question :
X is a trivalent metal . when treated with HCl , H gives Hydrogen , while its oxide undergoes neutralization.
16.5g of a mixture of X(s) and X2O3 (s) is allowed to react with 6M HCl(aq) . 0.0954dm3 of the acid is needed for both the metal and its oxide to undergo complete reaction.Based on this information , Deduce respectively the greatest value and the smallest possible value of the relative atomic mass of X

thx for any answer

Offline Borek

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Re:2005 A Level questions for me
« Reply #1 on: April 20, 2005, 05:47:47 AM »
Your sample contains x g of metal and (16.5 - x)g of oxide. Put y as the molar mass and create the equation describing amount of HCl needed for the complete reaction of the sample. It will have the from V = f(x,y) - everything else is a math.
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Offline AWK

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Re:2005 A Level questions for me
« Reply #2 on: April 20, 2005, 05:57:23 AM »
Hint
Treat this mixture as pure metal for the greatest number, and as pure oxide for the smallest one (85.6 - 61.6)
« Last Edit: April 20, 2005, 05:57:57 AM by AWK »
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