neutralization

My book say reaction of carbonate with acid can be regarded as neutralization,is that right?But as i know,neutralization is an acid-base reaction,but carbonate is not a base,then why my book say that?Thanks

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I think your book is wrong. As far as I know, neutralization is reaction OH- ions with H+ ions:

H+ + OH- --> H2O

but that doesn` t happen when a carbonate reacts with an acid.

SrCO3 + H2SO4 --> SrSO4 + H2CO3

Because the outcome of a carbonate-acid reaction yields an acid salt and water, your book regards this as a neutralization reaction, but that is an oversimplification, ignoring the status of "carbonic acid."

We regard 2 Na(OH) + H2SO4 > 2H2O + Na2SO4 as a neutralization reaction because the hydroxyl 2 (OH)- and 2H+ yield 2 H20 and the other ions, 2 Na+ and SO4-2 are left as aqueous species.

Now consider Ca(OH)2 + H2SO4 > 2 H2O + CaSO4 but the Ca+2 and SO4-2 are not left as aqueous ions because CaSO4 (plaster of paris) is fairly insoluble so after filtering it out, you are left with water-- neutralization.

Next consider Sr(NO3)2 + H2SO4 > SrSO4 + 2HNO3; in this reaction, the product of Sr+2 and SO4-2 in also markedly less soluble than the other ions and precipitates out; the only ions left in solution (in appreciable quanities) are the 2H+ and the 2 NO3-. In effect, the reaction generates a chalky precipitate (strontium sulfate) and solution of nitric acid. If you filtered the solution, you would be left with fairly pure nitric acid. Here the ionic species do not neutralize because NO3- generates a fairly high H+ count (giving a low pH because those are expressed as negative exponents: 10-3 is acidic while 10-9 is basic)

Now look at SrCO3 + H2SO4; combining these again generates insoluble SrSO4 but the ion CO3-2 is a transient species, that is it exists (if at all) only for microseconds because H2CO3 (carbonic acid) exists only under extreme pressure; typically at normal pressure H2CO3 > H20 + CO2. The latter of course is a gas and bubbles out of solution, thus you are left with H2O as the product of the reaction which is the appearance of neutralization, but SrCO3 + 2HI > SrI2 + H2O + CO2; here the Sr+2 and I- remain in solution, but the appearance of neutralization depends on the fact that "carbonic acid" is inherently unstable and breaks down into water and CO2, the latter of which as a gas boils off and leaves the reaction.

Is this clearer?

[quote="Martin17"]
Now look at SrCO3 + H2SO4; combining these again generates insoluble SrSO4 but the ion CO3-2 is a transient species, that is it exists (if at all) only for microseconds because H2CO3 (carbonic acid) exists only under extreme pressure; typically at normal pressure H2CO3 > H20 + CO2. The latter of course is a gas and bubbles out of solution, thus you are left with H2O as the product of the reaction which is the appearance of neutralization, but SrCO3 + 2HI > SrI2 + H2O + CO2; here the Sr+2 and I- remain in solution, but the appearance of neutralization depends on the fact that "carbonic acid" is inherently unstable and breaks down into water and CO2, the latter of which as a gas boils off and leaves the reaction.
[/quote]

Sorry, I didn`t understand; do you think reaction acids with carbonates is neutralisation or not :?:

Technically, as I understand the term, neutralization is an acid-base reaction in which the H+ of the acid and the (OH)- of the base combine to produce H2O, so carbonate reactions are technically NOT neutralizations, but because product of such ion exchange reactions, "carbonic acid," doesn't exist (at least for long) the resulting H2CO3 > H2O + CO2 and the loss of CO2 to the atmosphere results in H2O as the product, so it appears to be "neutralization" in a broader sense.

Sorry, in real life, unlike SAT tests, real answers are sometimes not cut and dry. The answer to the question very much depends on the definition of neutralization. The archaeologist Stuart Piggott once advised graduate students, "don't study answers, study questions." The terms in which a question is framed and the rules of the inquiry are more important than the immediate answer which is often subject to revision.

"Oxidation" is narrowly combining with O2 as in 2 Mg + O2 > 2MgO, but considerable light and heat are evolved in the reaction Fe + S > FeS so a good number of 19th- and early 20th-century texts included this reaction as "oxidation"; as our knowledge of chemistry became more sophisticated, "oxidation" came to be seen as any reaction in which a substance gave up electrons to an electron receiver (such as O2 or S) thus the question of whether Cl in the equation Cl2 + 2NaI > 2NaCl + I2 has been "oxidized" depends on what "oxidation" entails.

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