The metals like zinc, aluminium, iron and magnesium are added in different test tubes containing dilute hydrochloric acid. Answer the following questions based on your observations. Which of these metals reacted with the acid? Which of these metals reacted most vigorously? Is there any metal which did not react with the acid? Which gas is liberated during these reactions? How would you detect it? Is there any difference in the vigour of the reaction of the metals with acid?

The metals like aluminium, magnesium, zinc and iron will react with hydrochloric acid. This is because, they are reactive metals and can displace hydrogen from acids. The metals like aluminium and magnesium will react most vigorously with dilute hydrochloric acid. This is because, they are highly reactive metals. Therefore, they produce their corresponding salts such as aluminium chloride and magnesium chloride. No, all the given metals will react with dilute hydrochloric acid as they are reactive metals. Therefore, they produce their respective salt and liberate a gas. The gas liberated during such reaction will be the hydrogen gas. That is, in general, metals react with acids to form metal salt and hydrogen gas. We can detect the gas formed by keeping it near a burner. That is, when it is kept near a burner, it will burn with a pop-up sound. Yes, the vigour of the reaction depends on the nature of the metals. That is, highly reactive metals will react very vigorously with acids. The reactivity of the metals can be given using the reactivity series of metals.

E M B I B E

Science for Class 8 - Part 1>Chapter 7 - Metals>Exercise 7

Kerala Board Solutions for Chapter: Metals, Exercise 7: Exercise 7

Author:Kerala Board

Kerala Board Science Solutions for Exercise - Kerala Board Solutions for Chapter: Metals, Exercise 7: Exercise 7

Attempt the free practice questions on Chapter 7: Metals, Exercise 7: Exercise 7 with hints and solutions to strengthen your understanding. Science for Class 8 - Part 1 solutions are prepared by Experienced Embibe Experts.

Questions from Kerala Board Solutions for Chapter: Metals, Exercise 7: Exercise 7 with Hints & Solutions

MEDIUM

8th Kerala Board

IMPORTANT

Science for Class 8 - Part 1>Chapter 7 - Metals>Exercise 7>Q 1

Write down the products formed when zinc reacts with dilute hydrochloric acid.

HARD

8th Kerala Board

IMPORTANT

Science for Class 8 - Part 1>Chapter 7 - Metals>Exercise 7>Q 2

Write down the balanced chemical equation of the given reactions:

$Mg + 2 HCl \to$

$Fe + 2 HCl \to$

$2 Al + 6 HCl \to$

HARD

8th Kerala Board

IMPORTANT

Science for Class 8 - Part 1>Chapter 7 - Metals>Exercise 7>Q 3

Lemon and buttermilk contain acids. Explain why a stainless steel knife is preferred to an iron knife to cut lemons and also why it is not wise to store buttermilk in aluminium vessels.

HARD

8th Kerala Board

IMPORTANT

Science for Class 8 - Part 1>Chapter 7 - Metals>Exercise 7>Q 4

The metals like zinc, aluminium, iron and magnesium are added in different test tubes containing dilute hydrochloric acid. Answer the following questions based on your observations.