10th Class Science Metals and Non-metals Question Bank 10th CBSE Science Metals and Non-metals

  • question_answer    (a) Distinguish  between   ionic   and covalent  compounds   under  the following properties. (i) Strength   of   forces   between constituent elements. (ii) Solubility of compounds in water. (iii) Electrical conduction in substances. (b) Explain how the following metals are obtained from their compounds by the reduction process. (i)Metal M which is in the middle of the reactivity series. (ii) Metal N which is high up in the reactivity series. Give one example of each type.   


                      (a) (i) Ionic compounds have strong force of attraction between the oppositely charged ions (e.g., Na+ and ), so they are solids. Covalent compounds have weak force of attraction between their molecules, so they are usually liquids or gases. (ii)Ionic compounds are soluble in water but covalent compounds are insoluble in water. (iii) Ionic compounds conduct electricity when dissolved in water or when melted because  they contain ions (charged particles). But covalent compounds like glucose do not conduct electricity because they do not contain ions.                                                       (3) (b) (i) The metal M which is in the middle of the reactivity series (such as iron, zinc, lead, copper, etc.) is moderately reactive. Thus, to obtain such metals from their compounds, their sulphides and carbonates (in which they are present in nature) are first converted into their oxides by the process of roasting and calcination respectively,                      The metal oxides (MO) are then reduced to    the corresponding metals by using suitable    reducing agents such as carbon.                 For example, zinc metal can be obtained from its  oxide as follow                              (ii) The metal N which is high up in the reactivity   series (such as sodium, magnesium, calcium, aluminium, etc), is very reactive and cannot   be obtained from its compound by heating with carbon.                                Therefore, such metals are obtained by   electrolytic reduction of their molten salt.      For example, sodium is obtained by the electrolysis of molten sodium chloride  (NaCl).                                  At cathode At anode                         (2)

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