Understanding Reactions of Cations with Sodium Hydroxide and Aqueous Ammonia

What determines the color of the precipitate formed when sodium hydroxide is added to a solution containing cations?

• The pH of the solution

• The color of the cation

• The concentration of sodium hydroxide

• The temperature of the solution

Why do hydroxide ions react with positive ions in a solution?

• Because they have the same charge

• Because they are both insoluble

• Because they are both soluble

• Because they have opposite charges

Which hydroxides are generally soluble in water?

• No hydroxides are soluble

• Only hydroxides of transition metals

• Only hydroxides of sodium, potassium, and ammonium

• All hydroxides

What is the term for a substance that can react with both acids and bases?

• Amphoteric

• Acidic

• Basic

• Neutral

Which of the following hydroxides is amphoteric?

• Sodium hydroxide

• Calcium hydroxide

• Zinc hydroxide

• Magnesium hydroxide

What happens to amphoteric hydroxides in excess sodium hydroxide?

• They remain unchanged

• They evaporate

• They dissolve

• They form a new precipitate

Which cation forms a blue precipitate with sodium hydroxide?

• Copper

• Aluminum

• Iron(II)

• Zinc

What is the color of the precipitate formed by iron(III) ions with sodium hydroxide?

• Reddish-brown

• Green

• Blue

• White

Which of the following cations does not form a precipitate with sodium hydroxide?

• Calcium

• Sodium

• Magnesium

• Iron(II)

What is the significance of the 'ZAP' acronym in the context of hydroxides?

• It refers to hydroxides that are colored

• It refers to hydroxides that do not react with acids

• It refers to hydroxides that dissolve in excess sodium hydroxide

• It refers to hydroxides that are insoluble