Posts

Chapter-2 Acid And Base Class 10

Image
Most Important Questions and Answers of Chapter 2 In Class 10 CBSE Science  Question 1. With the help of an example explain what happens when a base reacts with a non- metallic oxide. What do you infer about the nature of non-metal oxide? (Board Term I, 2017) Answer: Oxides of non-metals react with bases to form salt and water. For example, the reaction between carbon dioxide and calcium hydroxide. Calcium hydroxide, which is a base, reacts with carbon dioxide to produce salt and water. Hence, oxides of non-metals are acidic in nature. Question 2. What is observed when carbon dioxide gas is passed through lime water (i) for a short duration? (ii) for a long duration? Also write the chemical equations for the reactions involved. (Board Term I, 2016) Answer: (i) When CO 2  is passed through lime water for short interval of time, it turns milky due to the formation of insoluble calcium carbonate. (ii) If CO 2  is passed for long duration through lime water, the white precipitate formed di
Post a Comment
Read more

Physics Chater 3 Class 9 CBSE /ICSE

Image
  Chapter 3 Laws of Motion Class 9 - Concise Physics Selina Solutions Exercise 3(A) Question 1 Explain giving two examples each of — (a) Contact forces, and (b) Non-contact forces. Answer (a) Contact Forces  — The forces which are applied on bodies by making a physical contact with them, are called  contact forces. Examples of contact force: Frictional force  — When a body slides (or rolls) over a rough surface, a force starts acting on the body in a direction opposite to the motion of the body, along the surface in contact. This is called  frictional force or force of friction. Normal reaction force  — When a body is placed on a surface, the body exerts a force downwards, equal to it's weight, on the surface, but the body does not move (or fall) because the surface exerts an equal and opposite force on the body normal to the surface which is called normal reaction force. (b) Non-Contact forces  — The forces experienced by bodies even without being physically in touch, are called 
Post a Comment
Read more

Class 9 History

Image
The Harappan Civilisation Class 9 - Total History & Civics Solutions Multiple Choice Questions Question 1 The period when man used both stone and copper tools is known as: Bronze Age Period Chalcolithic Period Mesopotamian Civilisation Period Egyptial Period Answer Chalcolithic Period Question 2 Name the term archaeologists use for a group of objects distinctive in style, usually found together within a specific geographic area and period of time. Civilisation Culture Period History Answer Culture Question 3 Which of the following insights about the Harappan Civilisation was provided by the citadel? There were public buildings for specific purposes. There was ceremonial bathing. There was overseas trade. The people were literate. Answer There were public buildings for specific purposes. Question 4 Which of the following is NOT a feature of the Dockyard? World's oldest dockyard Presence of mud brick platform Surrounded by wall of baked bricks Connected by channels to
Post a Comment
Read more