Acids, Alkalis, and Titrations

Flashcards about acids, alkalis, and titrations

What indicators are used to distinguish between acids and alkalis?

Litmus (red in acid, blue in alkali), phenolphthalein (colourless in acid, pink in alkali), and methyl orange (red in acid, yellow in alkali).

What colour does phenolphthalein turn in an alkaline solution?

Pink.

How is the pH scale used to classify solutions?

0-3 = strong acid, 4-6 = weak acid, 7 = neutral, 8-10 = weak alkali, 11-14 = strong alkali.

A solution has a pH of 11. How would you classify it?

Strong alkali.

What does universal indicator do?

It shows the approximate pH of a solution using colour.

What pH would a green universal indicator show?

Neutral (pH 7).

What ions do acids and alkalis produce?

Acids produce H+ ions, alkalis produce OH- ions.

What ions are produced by an alkali in water?

Hydroxide ions (OH-).

What happens when an alkali reacts with an acid?

A neutralisation reaction occurs.

What is the word equation for neutralisation?

Acid + alkali -> salt + water.

Why do we use a burette in titration?

To measure and add the acid accurately and slowly.