QUESTION BANK (2016-17)
CLASS-X
CHEMISTRY – (Carbon and its compound)
Q 1- Answer the following questions:
(1 marks)
1) Name the element whose allotropic form is graphite.
2) How does graphite act as a lubricant?
3) Write the names of any two isomers represented by the molecular formula C5H12.
4) Write down (i) structural formula, and (ii) electron-dot formula, of any one isomers of hexane (C6H14), other than
n-hexane.
5) Describe one reaction of ethanol.
6) Explain why, alkanes are excellent fuels.
7) Would you be able to check whether water is hard by using a detergent? Why?
8) Name the simplest ketone.
Q 2- Answer the following questions:
(2 marks)
9) (a) What is the general name of all the compounds made up of carbon and hydrogen ?
(b) Why does carbon form compounds mainly by covalent bonding?
10) (a) What is meant by catenation ? Name two elements which exhibit the property of catenation.
(b) Write the names and structural formulae of all the possible isomers of hexane.
11) (a) Give the general formula of an : (i) alkane (ii) alkene (iii) alkynes.
(b) Classify the following compounds as alkanes, alkenes and alkynes:
12) (a) Write the chemical equation of the reaction which takes place during the burning of ethanol in
air.
(b) Why is ethanol used as a fuel?
13) How would you convert?
(a) Ethanol into ethane?
(b) propanol into propanoic acid ?
14) What is the difference between two consecutive homologues?
(a) In terms of molecular mass ?
(b) In term of number and kind of atoms per molecule?
15) Draw the structures of the following compounds:
(a) Hexanal
(b) Butanone
(c) Ethanoic acid
(d) Bromopentane
16) Amongst saturated and unsaturated hydrocarbon which is more reactive and why ?
17) Complete the following equations:
(a) CH3CH2OH
Conc.H2SO4
170 o C
(b) CH3COOH + C2H5OH Conc.H2SO4
Q 3- Answer the following questions in brief:
(3 marks)
18) (a) What happen when methane reacts with chlorine ? Give equation of the reaction which takes place.
(b) What is hydrogenation? What is its industrial application?
19) (a) Explain the process of preparation of soap in laboratory.
(b) Why is common salt added during the preparation of soap?
(c) Why is soap is not suitable for washing clothes when the water is hard?
20) (a) How would you test for an alcohol ?
(b) Give the harmful effects of drinking alcohol?
(c) Explain why , methanol is much more dangerous to drink than ethanol.
21) (a) Why does the element carbon from a large number of carbon compounds ?
(b) Write down the structures and names of two isomers of butane.
4- Answer the following questions in detail:
(5 marks)
22) (a) Draw the structures of the following compounds :
i) Propanone
ii) Butanone
(b) Write the IUPAC names of the following:
i) HCHO
ii) CH3CHO
iii) CH3CH2CHO
iv) CH3CH2CH2CHO
(c) Which functional group is likely to be present in an organic compound having the molecular formula C4H10O ?
Write the formula of the organic compound.
23) (a) What is a homologous series ? Explain with an example.
(b) State two characteristics of a homologous series.
(c) The molecular formula of an organic compound is C18H36. Name its homologous series.
24) (a) Name the reaction which is usually used in the conversion of vegetable oil and fats. Explain the reaction
involved in detail. Write a chemical equation to illustrate your answer.
(b) What is saponification ? Write the chemical equation of the reaction involved in this process. Name all the
substances which take part in this process and also those which are formed.
(c) Why does micelle formation take place when soap is added to water ? Will a micelle be formed in other
solvents like ethanol also ?
25) (a) What happens when carbon burns in air? Write the chemical equation of the reaction which takes place.
(b) Why are coal and petroleum called fossil fuels?
(c) Explain how coal was formed in the earth.
(d) Describe how petroleum was formed in the earth.
(e) Name a fossil fuel other than coal and petroleum.
QUESTION BANK (2016-17)
CLASS-X
CHEMISTRY – (Periodic classification of elements)
Q 1- Answer the following questions :
(1 marks)
1. Name the Russian chemist who said that the properties of elements are a periodic function of their atomic
masses.
2. Name two elements whose properties were predicted on the basis of their position in Mendeleev’s periodic
table.
3. Which fundamental property is Mendeleev’s periodic table based on?
4. State modern periodic law of classification of elements.
5. List the position of metal and non-metal in the periodic table.
6. Amongst elements with atomic number 11 and atomic number 14, which has a bigger size atom.
7. An element ‘X’ has electronic configuration 2,8,8,1 while element ‘Y’ has electronic configuration 2,8,7. Which of
this is a metal?
8. Why is position of hydrogen not justified in the modern periodic table?
Q 2- Answer the following questions :
(2 marks)
9. Write the electronic configuration of the following elements and predict the group and period to which they
belong –
(a) Magnesium
(b) Potassium
(c) Carbon
(d) Silicon
10. List two important limitations of Mendeleev classification.
11. How are the short comings of Mendeleev’s periodic table overcome in modern periodic table?
12. Chlorine and Bromine are kept in the same group in the periodic table. Why?
13. How do atomic radii change
(a) On moving across the period?
(b) On moving down the group?
14. Chlorine has two isotopes Cl-35 and Cl-37. Would you place them in different slots because their atomic masses
are different or would you place them in the same position because their chemical properties are same?
15. In the periodic table, how does the tendency of atoms to lose electrons change on going from:
(i) Left to right across the period?
(ii) Top to bottom in a group?
16. In the modern periodic table, the element calcium is surrounded by elements with atomic numbers 12, 19, 21
and 38. Which of these elements has physical and chemical properties resembling those of calcium and why?
17. Amongst Lithium and potassium, which is larger in size and why?
Q 3- Answer the following questions in brief:
(3 marks)
18. What is Dobereiner’s law of triads? Explain with the help of one example of Dobenerier’s triad.
19. (a) State the periodic law on which Mendeleev’s periodic table was based. Why and how was this periodic law
changed?
(b) Explain why, the noble gases are placed in a separate group.
20. (a) How do the properties of eka-aluminium element predicted by Mendeleev compare with the actual
properties of gallium element? Explain your answer.
(b) What names were given by Mendeleev to the then undiscovered elements
(i) Scandium (ii) Gallium (iii) Germanium
21. An element ‘X’ belongs to group 2 and other element ‘Y’ belong to group 15 of the periodic table:
(i) What id the number of valence electrons in ‘X’?
(ii) What is the valency of ‘X’?
(iii) What is the number of valence electrons in ‘Y’?
(iv) What is the valency of ‘Y’
4- Answer the following questions in detail:
(5 marks)
22. (a) State modern periodic law.
(b) How does the electronic configuration of the atom of an element relate to its position in the modern
periodic table?
(c) How could the modern periodic law remove various anomalies of Mendeleev’s periodic table? Explain with
examples.
(d) Is it possible to have an element having atomic number 1.5 placed between hydrogen and helium?
(e) Name the scientist who prepared modern periodic table.
23. Roman was told that six elements A, B, C, D, E and F have atomic numbers of 2, 12, 20, 18, 4 and 10 respectively:
(a) Which of these elements belong to the same groups of the periodic table? Why?
(b) Which of these elements belong to the same periods of the periodic table? Why?
(c) Which of these elements are (i) Metals and (ii) Non-metals?
(d) Which of these elements are chemically (i) Reactive and (ii) Unreactive
(e) What values are displayed by Roman in answering the above questions?
24. There are three elements X, Y and Z having atomic numbers of 6, 16 and 19 respectively. Based on these
information, Rakhi has been asked to answer the following questions:
(a) In which group of the periodic table would you expect to find (i) Element X (ii) Element Y (iii) Element Z?
(b) Which two elements will form ionic bonds? Why?
(c) What will be the formula of ionic compound formed?
(d) Which two elements will form covalent bonds? Why?
(e) What values are displayed by Rakhi in answering the above questions?
25. (a) Explain why, the first period of the modern periodic table has only two elements where as second period has
eight elements.
(b) Why do elements in the same group show similar properties but the elements in different groups show
different properties?
(c) For each of the following triads, name the element with the characteristics specified below:
(i)
(ii)
Elements
Least atomic radius
F, Cl, Br
Li, Na, K
…………………………….
…………………………….
Chemically least reactive
……………………………….
……………………………….
(d) State one reason for keeping Fluorine and Chlorine in the same group of the periodic table.
(e) What are the merits of the modern periodic table of elements?