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Author Topic: Why does barium react with dilute hydrochloric acid but not sulphuric acid?  (Read 16643 times)

Offline miss_maple

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Topic : Acid & Bases

Qns : Why barium reacts with dilute hydrochloric acid but appears not to react with dilute sulphuric acid ?

Pls ans this quick. im having a test 2mr.

♥miss maple♥
« Last Edit: 10/12/2008 13:28:29 by BenV »


 

Offline lightarrow

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Topic : Acid & Bases

Qns : Why barium reacts with dilute hydrochloric acid but appears not to react with dilute sulphuric acid ?

Pls ans this quick. im having a test 2mr.

♥miss maple♥
H2SO4 reacts with Ba forming BaSO4 which is insoluble, so it forms a thin layer on the metal's surface, preventing a further action of the acid.
 

Offline miss_maple

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oh ok ! does this apply only to barium or does it apply to any other metals ?
« Last Edit: 11/12/2008 07:25:07 by miss_maple »
 

Offline lightarrow

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oh ok ! does this apply only to barium or does it apply to any other metals ?
Only to those metals which react with (dilute) H2SO4 forming an isoluble layer (sulphate, oxide, ecc). PbSO4 is also insoluble (but less insoluble than BaSO4). Note that, instead, concentrated H2SO4 does dissolve those sulphates because they react forming hydrogen sulphates, which are soluble:

BaSO4 + H2SO4 <--> Ba(HSO4)2

Aluminum also is insoluble in that acid because it forms a tick layer of Al2O3. Tin also should be insoluble. Other metals as Cu, Ag, Au, Pt, ecc., are too noble to react with a generic non-oxidant acid. Yes, someone could say that hot, conc. H2SO4 is oxidant too...
The story would be very long...
« Last Edit: 12/12/2008 19:48:52 by lightarrow »
 

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