Positive result

Definition

A test result showing that the ion being tested for is present.

Used by Edexcel

Specification 9.7C · Paper 2

A white precipitate is a positive result for sulfate ions. Acidification removes interference from carbonate ions, which could otherwise also form a white precipitate with barium ions. Sulfuric acid must not be used because it would add sulfate ions and could create a false positive.
Revise: Unknown Salt Identification

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GCSE Chemistry · key term

A test result showing that the ion being tested for is present.

Used by Edexcel

Specification 9.7C · Paper 2

A white precipitate is a positive result for sulfate ions. Acidification removes interference from carbonate ions, which could otherwise also form a white precipitate with barium ions. Sulfuric acid must not be used because it would add sulfate ions and could create a false positive.
Revise: Unknown Salt Identification

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