Adouble-displacement reaction occurs when the negative ion of me compound replaces the positive ion of the other compound to form two new compounds during a chemical reaction.

a. true
b. false

B. False

Explanation: A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.

Example:

Thus as we can see sodium ion is being replaced by ammonium ions   and thus positive ions replace positive ions only and not negative ions.

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

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tony (lordcaos066)

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explanation:

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