Skip to main content

5411test- sources,


Sample Paper – 2009
Class – X
Subject – Science
 


Q-1 TO Q-10 CARRIES 1 MARK EACH,Q-11 TO Q -17 CARRIES 2 MARK EACH,Q-18 TO Q-24 CARRIES 3 MARK EACH



  1. Why should magnesium ribbon be cleaned before burning in air?
  2. Why does the colour of copper sulphate solution change when an iron nail is dipped into it?
  3. Why is respiration considered as exothermic reaction explain?
  4. What is a skeletal chemical equation?
  5. Why does calcium donot occur in free state in nature?
  6. Name two non metals which are both brittle and non ductile?
  7. Why utensils made of aluminum do not corrode?
  8. Why is iron more useful when it is mixed with a little carbon?
  9. How one can increase the efficiency of conventional resource of energy?
  10. What are semi conductors?
  11. What is an alloy? Give composition of brass, solder.
  12. Why is CNG better fossil fuel then crude oil of coal?
  13. What is global warming? How it effect the existence of human population?
  14. What are advantages and diosadvantages of nuclear power plant?
  15. What is a balanced chemical equation? What is need to balance an equation?
  16. What are redox reactions? Explain with the help of two examples?
  17. Define  mineral, ore, gangue.
  18. How can we harness energy from oceans?
  19. Explain how biogas is formed?
  20. Draw a line diagram showing the various processes in the extraction of a metal?
  21. How can copper be extracted by electrolytic refining?
  22. Give reasons for following


  1. Metals are electropositive
  2. Nitrogen gas is used to preserve food
  3. Silver does not displace hydrogen from dilute HCl.


  1. What happens when


  1. Calcium reacts with water
  2. Iron reacts with steam
  3. Magnesium reacts with hot water
  4. Sodium reacts with water


  1. Explain the following reactions with examples


  1. Precipitation reactions
  2. Double decomposition reaction
  3. Photography reaction

 



-------------------------------------------------------------------------------------------------------
www.cbsekey.com
Other Educational Portals
English | cbse | Science | Mathematics


Labels:

Comments

Post a Comment

Popular posts from this blog

POLITICAL SCIENCE CLASS X CBSE - POLITICAL PARTIES

POLITICAL SCIENCE CLASS X CBSE POLITICAL PARTIES CHALLENGES TO POLITICAL PARTIES We know that how crucial political parties are for the democracy. They are the most visible face of the democracy and people blame them for whatever is wrong in the working of democracy. This is a case of our country too. Popular dissatisfaction and criticism has focused on four problem areas in the working of political parties. 1. LACK OF INTERNAL DEMOCRACY (with in the party): all over the world there is a tendency in the political parties towards the concentration of power in one or few leaders at the top. --parties do not keep membership registers, do not hold organizational meetings and conduct internal elections regularly. --ordinary members do not get sufficient information on what happens inside the party. --leaders assume greater power to make decisions in the name of party. --more than loyalty to the party principles and policies, personal loyalty to the lead...
12 comments
Read more

Chivvy (Class VII - English Honeycomb - Chapter 4)

NCERT Textbook Exercise Questions (Important only) Working with the Poem Q.2: The last two lines of the poem are not prohibitions or instructions. What is the adult now asking the child to do? Do you think the poet is suggesting that this is unreasonable? Why? Ans: In the last two lines the adults are asking the child to think himself and to be independent in taking decisions in some matters. The adults are asking to be firm and determined which is unreasonable because they themselves don’t allow the child to take any decision. They always tell him what to do or what not to do. So, their asking the child to make up his own mind is totally unreasonable. Q.3: Why do you think grown-ups say the kind of things mentioned in the poem? Is it important that they teach children good manners, and how to behave in public? Ans: The grown-ups say such kind of things to their children in order to teach those good manners, etiquettes and how to behave in public. It is important to teach the children ...
30 comments
Read more