An unknown substance turns blue litmus paper to red. Which additional test could be used to confirm the substance’s identity? It should turn phenolphthalein from colorless to pink because it is a base. It should turn phenolphthalein from pink to colorless because it is a base. It should turn methyl orange to orange because it is an acid. It should turn methyl orange to red because it is an acid.

Respuesta :

Blue litmus paper turning red means that the solution where the litmus paper was submerged is an acidic solution with a pH of less than 7. Another verification of the nature of the solution is the turning to red of methyl orange in acidic solutions. The answer then is D. 

The substance that turns blue litmus red should turn methyl orange to red because it is an acid.

What is an acid?

An acid is a substance that produces hydrogen ions as the only positive ions when dissolved in water.

Properties of acid include :

  • acids turn blue litmus red
  • are corrosive
  • are sour in taste

Therefore, the substance that turns blue litmus red is an acid:

It should turn methyl orange to red because it is an acid.

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