Metal Reactions with Dilute Acids

What happens when a metal reacts with a dilute acid?

• No reaction occurs

• Formation of a metal oxide and water

• Formation of a base and oxygen gas

• Formation of a salt and hydrogen gas

Give an example of a metal that reacts with dilute hydrochloric acid.

• Gold

• Iron

• Aluminum

• Zinc

What gas is usually evolved when a metal reacts with a dilute acid?

• Carbon dioxide

• Oxygen gas

• Hydrogen gas

• Nitrogen gas

State the general word equation for the reaction between a metal and a dilute acid.

• Metal + Acid → Salt + Oxygen gas

• Metal + Dilute Acid → Water + Hydrogen gas

• Metal + Dilute Acid → Salt + Carbon dioxide

• Metal + Dilute Acid → Salt + Hydrogen gas

Why do some metals react with acids while others do not?

• Metals react with acids if they are more reactive than hydrogen, displacing hydrogen to form metal salts and hydrogen gas.

• Metals react with acids only if they are in liquid form, displacing hydrogen to form metal salts and hydrogen gas.

• Metals react with acids due to their coloration, forming metal salts and hydrogen gas.

• Metals react with acids if they are less reactive than hydrogen, displacing hydrogen to form metal salts and hydrogen gas.

Explain why copper does not react with dilute hydrochloric acid.

• Copper reacts vigorously with dilute hydrochloric acid

• Copper forms an insoluble layer that protects it from the acid

• Copper does not react with dilute hydrochloric acid because it is less reactive than hydrogen.

• Copper is highly soluble in hydrochloric acid

What is the color change observed when iron reacts with dilute sulfuric acid?

• Black precipitate of iron(II) sulfide

• Greenish-yellow precipitate of iron(III) sulfate

• Colorless solution

• Reddish-brown precipitate of iron(II) sulfate

How can you test for the presence of hydrogen gas during a metal-acid reaction?

• Perform the 'pop' test by placing a lighted splint near the reaction vessel.

• Shake the reaction vessel vigorously to observe any gas bubbles.

• Use a pH indicator to detect the presence of hydrogen gas.

• Listen for a high-pitched sound to confirm the release of hydrogen gas.

What is the role of the acid in the reaction with a metal?

• To react with the metal to form metal salts and hydrogen gas.

• To increase the reaction rate

• To form metal oxides

• To prevent the reaction with the metal

Why is it important to carry out the reaction of metals with dilute acids in a well-ventilated area?

• To increase the reaction rate

• To enhance the color change of the reaction

• To reduce the cost of the experiment

• To prevent the build-up of potentially harmful gases like hydrogen.