Skip to main content

Chapter 1. Chemical Reaction and Equations

When a copper strip is placed in a solution of silver nitrate, copper nitrate and silver are formed. Name this reaction. (1 mark)

2. Give one example of a redox reaction which is also a combination reaction. (1 mark)

3. Name two anti-oxidants which are usually added to fat and oil containing foods to prevent rancidity. (1 mark)

4. When SO2 gas is passed through saturated solution of H2S, the following reaction occurs: SO2 + 2H2 S ------> 2HO2 + 3S (1mark)
In this reaction, which substance is oxidised and which one is reduced?

5. When hydrogen is passed over heated CuO, brown copper is deposited. Which element is reduced. (1 mark)

6. A solution of CuSO4 was kept in an iron pot. After few days, the iron pot was found to have a number of holes in it. Write the equations of the reaction took place. Explain this reaction in terms of reactivity. (2 marks)

7. What happens when silver chloride is exposed to sun light? Write a chemical equation for this reaction. Give one use of such a reaction. (2 marks)

8. What is meant by double displacement reaction? Explain with the help of an example (2 marks)

9. Why is double the amount of a gas collected in one of the test-tubes in the electrolysis of water experiment? Name this gas. (2 marks)

10. Write balanced chemical equation with state symbols for the following reaction: (2 marks) (i) Solution of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride.(ii) Sodium hydroxide solution (in water) reacts with hydrochloric aid solution (in water) to produce sodium chloride solution and water.

11. Why is respiration reaction considered as an exothermic reaction? Explain. (2 marks)

12.
(a)What is the general name of the chemicals which are added to fat and oil containing foods to prevent the development of rancidity?
(b)What are anti-oxidants? Why are they added to fat and oil containing foods?
(c) Explain, why food products containing fats and oils.

Comments

Popular posts from this blog

The Missing Mail | Class IX - Interact in English

NCERT / CBSE Literature Reader for English Course (Communicative) Important Exercise Questions Q.3: (a) Why is Ramanujam worried about getting his daughter married? Give four reasons. (b) How does the postman console and guide Ramanujam and his family during each of the instances you have listed in 3 (a)? Ans 3(a): Ramanujam is worried as he could not find a suitable match to marry his daughter off which was getting delayed because of different reasons. The four causes of his worriedness are - (i) Sometimes horoscopes did not match, (ii) Sometimes the girl’s appearance were not approved, (iii) At times there were problems of too much dowry and other financial matters, (iv) The season was closing with only three more auspicious dates left, whereas, he was not able to finalise any alliance by that time. Ans 3(b): First instance - When Ramanujam said that horoscopes did not agree Thanappa consoled and guided him by saying that he should not utter inauspicious words and when the God wills

Carbon and it's Compounds

Introduction Carbon is an element which is of immense significance to us in both its elemental form and in the combined form. Bonding in Carbon - The Covalent Bond Although there are more than hundred elements around us we do not find these elements in their native form in nature. This is because most of these elements are highly reactive. Properties of Covalent Compounds A covalent bond can be formed in different ways. When a bond is formed by mutual sharing of one pair of electrons it is known as a 'single covalent bond', or simply 'a single bond'. Types of Covalent Bonds Types of covalent bonds are Single Bond, Double Bond , Triple Bond. Tetravalency in Carbon A carbon atom has a total of six electrons occupying the first two shells, i.e., the K-shell has two electrons and the L-shell has four electrons. Allotropes of Carbon The existence of one element in different forms, having different physical properties, but similar chemical properties is known as allotropy. Am

ENGLISH (Communicative) Sample Question Paper 5

Sample Paper – 2009 Class – XSubject – ENGLISH (Communicative) General instructions: The paper consist of FOUR sections: SECTION A (READING) - 20 Marks SECTION B (WRITING) - 30 Marks SECTION C (GRAMMAR) - 20 Marks SECTION D (LITERATURE) - 30 Marks Attempt all the questions. Do not write anything on the question paper. All the answers must be correctly numbered as in the question paper. And written in the answer sheets provided to you. Attempt all questions in each section before going on to the next section. Read each question carefully and follow the instructions. Strictly adhere to the word limit given with each question. Marks will be deducted for exceeding the word limit. SECTION A (READING) – 20 MARKS A1. Read the following passage and answer the following questions: [12] THE TUITION TRAP 1. Given the general awareness of the woeful condition of our State sch