Q17 of 27 Page 1

Write the chemical formula and name of the compound which is the active ingredient of all alcoholic drinks. List its 2 uses. Write chemical equation and name of the product formed when this compound reacts with-

(i) sodium metal


(ii) hot conc. Sulphuric acid


OR


What is methane? Draw its electron dot structure. Name the type of bonds formed in this compound. Why are such compounds:


(i)poor conductors of electricity? and


(ii) have low melting and boiling points? What happens when this compound burns in oxygen?


Ethanol or Ethyl alcohol is the active ingredient in all of the alcoholic drinks. Ethanol has the formula, C2H5OH.

Uses: Ethanol is used in medical wipes and in antibacterial hand sanitizer.


Ethanol is used to prepare medicines like tincture of iodine, cough syrups, and tonics.


i) The compound formed is called Sodium ethoxide.


ii) The compound formed is known as ethene.


OR


Methane (CH4) is a chemical compound which contains one carbon atom, surrounded by four hydrogen atoms. Methane is a greenhouse gas, and is produced by cows and landfill sites.


The type of bond present in methane is single covalent bond.


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i) Compounds containing covalent bonds are poor conductors of electricity because no free electrons or free ions are present.


ii) They have low melting and boiling points because of weak Vander Waal’s force of attraction.


When methane reacts with oxygen, the following reaction occurs:


CH4 + 2O2 → CO2 + 2H2O


Carbon dioxide and water are produced.


More from this chapter

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15

What is water harvesting? List 2 main advantages associated with water harvesting at the community level. Write 2 causes for the failure of sustained availability of groundwater.

 16

(a) List in tabular form 3 chemical properties on the basis of which we can differentiate between a metal and a non-metal.

(b) Give reasons for the following:


(i) Most metals conduct electricity well.


(ii) The reaction of iron(II) oxide [Fe2O3] with heated aluminium is used to join cracked machine parts.


 18

Define pollination. Explain the different types of pollination. List two agents of pollination? How does suitable pollination lead to fertilization?

OR


(a) Identify the given diagram. Name the parts 1 to 5



(b) What is contraception? List three advantages of adopting contraceptive measure.


 19

An object is placed at a distance of 60 cm from a concave lens of focal length 30 cm.

(i) use lens formula to find the distance of the image from the lens


(ii) List 4 characteristics of the image (nature, position, size, erect/inverted) formed by the lens in this case.


(iii) Draw ray diagram to justify you answer of part (ii).