Q Water in a stream after rain contains air bubbles,salt,calcium carbonate,sand grains,straw pieces and unfilterable clay particles.select from amongst these one examples each of a solvent, a solute, a suspe nsion and a colloid.
Q a compound A changes directly from solid to gaseous state on heating.With the help of a labelled diagram describe the process used for the separation of component A from NaCI.
Q suggest a way to determine whether a colourless liquid is pure water or a solution of salt or sugar in water, without tasting the liquid.
Q identify tge dispersed phase and dispersing medium of the following:
a) milk b) latex c) sponge. d)sprays
Q label each of the following as either chemical or physical change:
i) corrosion of aluminium metal
ii) pulverising aspirin tablet
iii)digestion of a candy bar
iv) making of a magnet from iron piece
Q classify the following into homogenous or heterogeneous mixtures
i) milk ii)sugar solution iii)concrete iv)blood
Q explain the following with examples
i) tyndall effect
ii) brownian motion
Q air is a chemical compound or mixture? Support your answer by suitable examples.
Q can physical and chemical changes occur together.illustrate your answer.
Q state three prominent properties of metals which are not shown by non metals.
Q what is chromatography?give its application.
Q during rainy season,the river water becomes muddy.it cannot be made fit for drinking purposes just by decantation or filtration.
Now answer the following questions
i)what makes the water muddy?
ii)why can't muddy water be made purified by either decantation or filtration?
iii) suggest two methods to make muddy water fit for drinking purposes.
Q calculate the mass of sulphuric acid present in 100 ml of 15% mass by mass solution of sulphuric acid.(density=1.10g/ml)
Q how does fractional distillation differ from distillation?draw a labelled diagram of the apparatus used for fractional distillation.
Q differentiate between the following
i)solution,suspension and colloid
ii)homogenous and heterogeneous mixture
iii) compound and mixture
iv)physical and chemical change
Q is 22 carat gold a mixture or an element?give reason.
Q can we separate a mixture of camphor and naphthalene by sublimation?give reason to support your answer
Q explain how water reaches to your house from the reservoir with the help of a diagram.
Q how much water must be added to 20g pf sugar to obtain 20% sugar solution.
Q how can we obtain different gases from air?arrange the gases present in the air in the decreasing order of their boiling points.
Q discuss briefly the principle,theory and applications of the techniques used for the separation of following mixtures
i) two immiscible liquids
ii) two miscible liquids whose boiling points differ by more than 25°c.
Q define the term solubility.discuss the effect of temperature and pressure on the solubility of gases in liquid.
Answers
Answered by
51
1 answer
it's a suspension.
2 no answer
it's an activity
3 answer
three ways to decide if it's pure or not
1st check boiling point
2nd check freezing point
3rd check if it conducts electricity
4 answer
milk - liquid fat dispersed in water oil drops in water
sponge - bubbles dispersed in solid
spray - liquid particles in gas
latex - solid into solid natural rubber in synthetic
5 answer
corrosion of aluminium metal - chemical
pulverising aspirin tablet - physical
digestion of a candy bar - chemical
making of a magnet from iron piece - physical
6 answer
Milk-heterogeneous
Sugar solution- homogenous
Concrete-heterogeneous
Blood-heterogenous
7 answer
TYNDAL EFFECT
The phenomenon of scattering of light by the colloidal particles due to which the path of beam is illuminated by a bluish light when seen at right angle to the path of light, is called Tyndall effect
BROWNIAN MOTION
When colloidal solution are viewed under powerful ultra microscope, then colloidal particles are moving rapidly is zig-zag directions.
8 ANSWER
Air is considered as mixture for the following reasons ;
1. Air can be separated into its components like N2, O2 , Argon and CO2 by the process of fractional distillation of liquid air.
2. Air shows the properties of all the gases present in the atmosphere.
3.Air does not have a fixed formula.
9 Answer
yes it's possible
When a candle burns, both physical & chemical changes occur.
10 Answer
three prominent proporties are lusture, hardness, ductile and
malleablity.
11 Answer
Chromatography
is a technique for the separation of a mixture by passing it in solution or suspension through a medium in which the components move at different rates.
12 no answer
it's way too easy
13 gold
24 caret gold is made up of pure gold so it is the pure metallic molten gold which can be considered as an element but in 22caret gold the gold is only 22 caret and the rest 2 carets are the other metals So, 22 caret gold is a type of mixture.
happy to help
it's a suspension.
2 no answer
it's an activity
3 answer
three ways to decide if it's pure or not
1st check boiling point
2nd check freezing point
3rd check if it conducts electricity
4 answer
milk - liquid fat dispersed in water oil drops in water
sponge - bubbles dispersed in solid
spray - liquid particles in gas
latex - solid into solid natural rubber in synthetic
5 answer
corrosion of aluminium metal - chemical
pulverising aspirin tablet - physical
digestion of a candy bar - chemical
making of a magnet from iron piece - physical
6 answer
Milk-heterogeneous
Sugar solution- homogenous
Concrete-heterogeneous
Blood-heterogenous
7 answer
TYNDAL EFFECT
The phenomenon of scattering of light by the colloidal particles due to which the path of beam is illuminated by a bluish light when seen at right angle to the path of light, is called Tyndall effect
BROWNIAN MOTION
When colloidal solution are viewed under powerful ultra microscope, then colloidal particles are moving rapidly is zig-zag directions.
8 ANSWER
Air is considered as mixture for the following reasons ;
1. Air can be separated into its components like N2, O2 , Argon and CO2 by the process of fractional distillation of liquid air.
2. Air shows the properties of all the gases present in the atmosphere.
3.Air does not have a fixed formula.
9 Answer
yes it's possible
When a candle burns, both physical & chemical changes occur.
10 Answer
three prominent proporties are lusture, hardness, ductile and
malleablity.
11 Answer
Chromatography
is a technique for the separation of a mixture by passing it in solution or suspension through a medium in which the components move at different rates.
12 no answer
it's way too easy
13 gold
24 caret gold is made up of pure gold so it is the pure metallic molten gold which can be considered as an element but in 22caret gold the gold is only 22 caret and the rest 2 carets are the other metals So, 22 caret gold is a type of mixture.
happy to help
Answered by
8
Answer:
That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth. ... Oneatmosphere is 1,013 millibars, or 760 millimeters (29.92 inches) of mercury.Atmospheric pressure drops as altitude increases.
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