Download App

Is Matter Around Us Pure ? — Science STD 9 — Question

Rajasthan BoardEnglish MediumSTD 9ScienceIs Matter Around Us Pure ?4 Marks
Question
$A, B$ and $C$ are all liquids. Liquid $A$ has a comparatively low boiling point. On heating, liquid a vaporizes completely without leaving behind any residue. Liquid $A$ is being used increasingly as a fuel in motor vehicles either alone or by mixing with petrol. Liquid $B$ has a very high boiling point. It also vaporizes completely on heating, without leaving any residue. Liquid $B$ is a conductor of electricity and used in making thermometers. Liquid $c$ has a moderate boiling point. On heating, liquid $C$ vaporises leaving behind a white solid $D$ which is used in cooking vegetables. The condensation of vapours from $C$ give a liquid $E$ which turns anhydrous $CuSO_4$ to blue.
  1. Which liquid could be an element? Name this element.
  2. Which liquid could be a mixture? Name this mixture.
  3. Which liquid could be a compound? Name this compound.
  4. What could the solid $D$ be?
  5. What do you think is liquid $E$?
✓

Answer

  1. Liquid $B$ has a very high boiling point. It also vaporises on heating. It is a conductor of electricity and is used in making thermometers. So, $B$ could be an element. Further, liquid $B$ is mercury as mercury is a liquid metal, which expands on heating and is used extensively in thermometers.
  2. Liquid $C$ has a moderate boiling point. It could be a mixture. It is a salt solution because when $C$ is heated, it vaporises and leaves behind a white solid $($salt$),$ which is used in the process of cooking.
  3. Liquid $A$ is used in motor vehicles as fuel, either alone or after mixing with petrol. It could be a compound because on heating, it does not leave any residue. It is alcohol as alcohol is being used in motor vehicles nowadays.
  4. Solid $D$ is sodium chloride. It is also known as common salt and is added in food.
  5. Liquid $E$ is water as, on heating, liquid $C,$ which is a salt solution, leaves water vapours. On condensing these vapours, we obtain pure water. When water is mixed with anhydrous copper sulphate, we obtain a blue colour solution. This is because of the formation of hydrated copper sulphate solution.
$\text{CuSO}_4+5\text{H}_2\text{O}\xrightarrow{\ \ \ \ \ \ \ \ \ \ \ \ }\text{CuSO}_4\cdot5\text{H}_2\text{O}$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ {^\text{hydrated copper sulphate}}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Que-Ans (Each of 4 Mark )" from Is Matter Around Us Pure ?→Is Matter Around Us Pure ? — all question types→Science STD 9 question papers→Rajasthan Board STD 9 question papers→Rajasthan Board question paper generator→

Similar questions

A car is travelling along the road at $8ms^{-1}.$ It accelerates at $1ms^{-2}$ for a distance of $18m.$ How fast is it then travelling?
→
Describe structure and functions of bone.
→
An element $X$ forms the following compounds with hydrogen, carbon and oxygen:
$H_2X, CX_2, XO_2, XO_3$
→
State Newton’s third law of motion and give two examples to illustrate the law.
→
Discuss the conservation of momentum in each of the following cases:
  1. A rocket taking off from ground.
  2. Flying of a jet aeroplane.
→
How are simple tissues different from complex tissues in plants?
→
Study the speed-time graph of a car given alongside and answer the following questions:
  1. What type of motion is represented by OA?
  2. What type of motion is represented by AB?
  3. What type of motion is represented by BC?
  4. What is the acceleration of car from O to A?
  5. What is the acceleration of car from A to B?
  6. What is the retardation of car from B to C?
→
How could you  convince a small child that when ou speak, it is not necessary for air to travel from your mouth to the ear of a listener?
→
If the distance between two masses is increased by a factor of $5,$ by what factor would the mass of one of them have to be altered to maintain the same gravitational force? Would this be an increase or decrease in the mass?
→
A stone is dropped from a height of $20m.$
How long will it take to reach the ground?
→