Permanent hardness of water can be removed by

A. Boiling

B. Adding Ca(OH)2

C. Boiling it with Na2CO3

D. None of these

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  1. The difference between saponification value and acid value is
  2. Phosphoric acid is prepared from
  3. Which is a high grade pulp?
  4. Hydrogenation of edible vegetable oils
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  6. Favourable conditions for the liquefaction of gases in general are
  7. Pick out the wrong statement.
  8. Which form of sulphur is the most stable at room temperature?
  9. __________ is an ore of lead.
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  13. Hydrazine is used in water treatment for the removal of
  14. Refractory bricks having high thermal conductivity is desirable, when it is to be used in the
  15. Higher viscosity index of a lubricating oil denotes
  16. The main use of activated carbon in water treatment is to control
  17. In industrial nomenclature, alcohol means
  18. Which of the following is used as a coagulant in water treatment?
  19. 'Synthesis gas' meant for the synthesis of organic compound is a variable mixture of
  20. Lindane is
  21. Sodium salt of higher molecular weight fatty acid is termed as the __________ soap.
  22. In multistage equilibrium conversion of SO2 to SO3 (2SO2 + O2 2SO3), the reverse reaction becomes appreciable…
  23. Oil is a/an
  24. Coke oven gas consists mainly of
  25. With increase in temperature, the equilibrium constant at constant pressure (Kp) for oxidation of sulphur…
  26. Most widely and commonly used coagulant for the removal of suspended impurities in water is
  27. Viscosity index improver (like polystyrene or polyisobutylene) is added to lubricant to
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