Page 222 - Chemistry ICSE Class X

208 ICSE Chemistry – 10
Q 12. )KXG CRRTQRTKCVG UEKGPVKſE TGCUQPU HQT VJG HQNNQYKPI UVCVGOGPV [ICSE 2015]
(i) Zinc oxide can be reduced to zinc by using carbon monoxide, but aluminium oxide cannot be reduced by a
reducing agent.
Q 13. (i) For each of the substance listed below, describe the role played in the extraction of aluminium. [ICSE 2015]
(1) Cryolite (2) Sodium hydroxide (3) Graphite.
(ii) Explain why:
(1) In the electrolysis of alumina using the Hall Heroult’s process, the electrolyte is covered with powdered
coke.
(2) Iron sheets are coated with zinc during galvanization.
Q 14. Choose the correct answer from the options given below: [ICSE 2016]
The two main metals in Bronze are:
(A) Copper and zinc (B) Copper and lead
(C) Copper and nickel (D) Copper and tin
Q 15. Identify the term/substance in the following: [ICSE 2016]
The method used to separate ore from gangue by preferential wetting.
Q 16. K 0COG VJG UQNWVKQP WUGF VQ TGCEV YKVJ $CWZKVG CU C ſTUV UVGR KP QDVCKPKPI RWTG CNWOKPKWO QZKFG KP VJG
Baeyer’s process. [ICSE 2016]
(ii) Write the equation for the reaction where the aluminium oxide for the electrolytic extraction of aluminium
is obtained by heating aluminium hydroxide.
(iii) Name the compound added to pure alumina to lower the fusion temperature during the electrolytic reduction
of alumina.
(iv) Write the equation for the reaction that occurs at the cathode during the extraction of aluminium by
electrolysis.
(v) Explain why it is preferable to use a number of graphite electrodes as anode instead of a single electrode,
during the above electrolysis.
Q 17. (i) From the list of terms given, choose the most appropriate term to match the given description. (calcination,
roasting, pulverisation, smelting) [ICSE 2017]
%TWUJKPI QH VJG QTG KPVQ C ſPG RQYFGT
(2) Heating of the ore in the absence of air to a high temperature.
Q 18. Name the following: [ICSE 2017]
(i) The process of coating of iron with zinc.
(ii) An alloy of lead and tin that is used in electrical circuits.
(iii) An ore of zinc containing its sulphide.
(iv) A metal oxide that can be reduced by hydrogen.
Q 19. Answer the following questions with respect to the electrolytic process in the extraction of aluminium: [ICSE 2017]
(i) Identify the components of the electrolyte other than pure alumina and the role played by each.
(ii) Explain why powdered coke is sprinkled over the electrolytic mixture.
Q 20. Give one word or a phrase for the following statement: [ICSE 2018]
The process by which sulphide ore is concentrated.
Q 21. Write a balanced chemical equation for the following: [ICSE 2018]
Action of heat on aluminum hydroxide.
Q 22. Fill up the blank with the correct choice given in brackets. [ICSE 2018]
The most common ore of iron is ________________. (calamine/haematite)
Q 23. Name the main component of the following alloys: [ICSE 2018]
(i) Brass (ii) Duralumin
Q 24. (i) Name the most common ore of the metal aluminum from which the metal is extracted. Write the chemical
formula of the ore.
KK 0COG VJG RTQEGUU D[ YJKEJ KORWTG QTG QH CNWOKPWO IGVU RWTKſGF D[ WUKPI EQPEGPVTCVGF UQNWVKQP QH CP
alkali.
(iii) Write the equation for the formation of aluminum at the cathode during the electrolysis of alumina. [ICSE 2018]