Clark's method for removal of temporary hardness in water uses
calcium hydroxide
washing soda
calcium chloride
zeolite
Correct Answer :
A. calcium hydroxide
Related Questions
Nitrous oxide used as anaesthetic is usually mixed with
ethyl alcohol
chloroform
oxygen
methyl alcohol
Which one of the following is present in the largest amount in terms of per cent by mass in the earth's crust?
Silicon
Oxygen
Carbon
Calcium
When ants bite, they inject
glacial acetic acid
methanol
formic acid
stearic acid
Consider the following statements: Hard water is not suitable for
1) drinking
2) washing clothes with soap
3) use in boilers
4) irrigating crops
Which of these statements are correct?
1 and 3
2 and 3
1, 2 and 4
1, 2, 3 and 4
Vinegar is an aqueous solution of
oxalic acid
citric acid
acetic acid
hydrochloric acid
The malarial parasite was discovered by
Sir Ronald Ross
Sir Francis Haig
Dr Jagadish Chandra Bose
Sir CV Raman
Lead pencils contain
white lead
graphite
red lead
coke
The gas evolved when ammonium nitrate is heated is
nitrogen
nitric oxide
nitrogen peroxide
nitrous oxide
High temperature thermometers use
sodium amalgam
an alloy of sodium and potassium
silver amalgam
calcium amalgam
Iodine in alcohol is known as
quick lime
tincture iodine
rectified spirit
None of these
Heated saw dust catches fire when a drop of concentrated nitric acid is added to it. This is due to
dehydration
oxidation
reduction
dehydrogenation
Hard water does not lather well with soap because
it contains carbonates of calcium and magnesium
it contains sodium chloride
it is highly coloured
it contains suspended impurities
The main element used in the vulcani-sation of rubber is
nickel
copper
sulphur
graphite
Leakage in Liquefied Petroleum Gas (LPG) cylinders is easily detected by adding
mercaptans
propylene
carbon disulphide
phosgene
The formula for cane sugar is
C6H12O6
C2H5OH
C12H22O11
C7H8O
Quick lime has the formula
CaO
Ca(OH)2
NaOH
Na2CO3
Compounds containing only carbon and hydrogen are called
carbohydrates
carbides
hydrocarbons
carbonyls
Mortar contains cement and sand in the ratio of
1 : 1
1 : 2
2 : 3
1 : 3
In photography, the compound or nitrogen used is
Potassium nitrate
Silver nitrate
Ammonium carbonate
Ammonium bicarbonate
Iron is coated with zinc to prevent rusting. The process is called
annealing
tempering
calcining
galvanising
Solder is an alloy of
tin and copper
tin and lead
tin and zinc
tin, copper and zinc
Argyrol used as eye ointment is a solution of
hydrogen peroxide
silver nitrate
tincture iodine
m-cresol
Gold dissolves in aqua regia due to the formation of
chloro auric acid
auric chloride
gold nitrate
aurous chloride
Solid carbon dioxide is used
as a drying agent
as a refrigerant
as an antiseptic
as a bleaching agent
Which of the following cannot be used for the preparation of soap?
oleic acid
acetic acid
palmitic acid
stearic acid
Brass contains
copper and tin
aluminium and magnesium
copper and zinc
copper, tin and zinc
Glass articles are annealed so that
they may appear better
they can resist the action of acids and alkalies
they lose their brittleness
they can withstand temperature shocks
In the making of jewels, gold is usually mixed with
zinc
tin
copper
aluminium
Setting of cement is due to
hydration
dehydration
dialysis
osmosis
Galvanising is the process of coating
iron with zinc
zinc with iron
copper with silver
silver with gold