NCERT Exemplar Class 6 Science Chapter 4 Sorting Materials into Groups

NCERT Exemplar Class 6 Science Chapter 4 Sorting Materials into Groups are part of NCERT Exemplar Class 6 Science. Here we have given NCERT Exemplar Class 6 Science Solutions Chapter 4 Sorting Materials into Groups.

NCERT Exemplar Class 6 Science Solutions Chapter 4 Sorting Materials into Groups

Multiple Choice Questions

Question 1.
An iron nail is kept in each of the following liquids. In which case would it lose its shine and appear dull?
(a) Mustard oil
(b) Soft drink
(c) Coconut oil
(d) Kerosene
Solution:
(b) : Soft drinks contain water, carbon dioxide and acid due to which iron nail is corroded and appears dull.

Question 2.
Pick one material from the following which is completely soluble in water.
(a) Chalk powder
(b) Tea leaves
(c) Glucose
(d) Sawdust
Solution:
(c): Glucose is completely soluble in water.

Question 3.
You are provided with the following materials
(i) magnifying glass
(ii) mirror
(iii) stainless steel plate
(iv) glass tumbler.
Which of the above materials will you identify as transparent?
(a) (i) and (ii)
(b) (i) and (iii)
(c) (i) and (iv)
(d) (iii) and (iv)
Solution:
(c): Magnifying glass and glass tumbler are transparent.

Question 4.
Boojho found a bag containing the following materials.
(i) Mirror
(ii) Paper stained with oil
(iii) Magnet
(iv) Glass spectacles
Help Boojho in finding out the material(s) which is/ are opaque.
Solution:
(a) (i) only
(b) (iv) only
(c) (i) and (iii)
(d) (ii) and (iv)
Solution:
(c): Mirror is opaque since it is painted on one side. Magnet is opaque since it is made up of iron metal.

Question 5.
While doing an activity in class, the teacher asked Paheli to .handover a translucent material. Which among the following materials will Paheli pick and give her teacher?
(a) Glass tumbler
(b) Mirror
(c) Muslin cloth
(d) Aluminium foil
Solution:
(c): Glass tumbler is transparent, mirror and aluminum foil are opaque while muslin cloth is translucent since we can see through it though not clearly.

Question 6.
Which pair of substances among the following would float in a tumbler half filled with water?
(a) Cotton thread, thermocol
(b) Feather, plastic ball
(c) Pin, oil drops
(d) Rubber band, coin
Solution:
(b): Feather and plastic ball will float on water because they are lighter than water.

Question 7.
Which among the following are commonly used for making a safety pin?
(a) Wood and glass
(b) Plastic and glass
(c) Leather and plastic
(d) Steel and plastic
Solution:
(d): Steel and plastic are used for making safety pins. Steel can be moulded to get sharp points and plastic is used to seal the edges.

Question 8.
Which of the following materials is not lustrous?
(a) Gold
(b) Silver
(c) Wood
(d) Diamond
Solution:
(c): Wood is not a crystalline substance and has no lusture.

Question 9.
Which of the following statements is not true?
(a) Materials are grouped for convenience.
(b) Materials are grouped to study their properties.
(c) Materials are grouped for fun.
(d) Materials are grouped according to their uses.
Solution:
(c): Materials are not grouped for fun. They are grouped for convenience, to study their properties and according to their uses in systematic manner.

Question 10.
Find the odd one out from the following.
(a) Tawa
(b) Spade
(c) Pressure cooker
(d) Eraser
Solution:
(d) : Tawa, pressure cooker and spade are made up of metal while eraser is made up of rubber.

Question 11.
Which type of the following materials is used for making the front glass (wind screen) of a car?
(a) Transparent
(b) Translucent
(c) Opaque
(d) All the above
Solution:
(a): Transparent glass is used for making the wind screen of a car so that everything can be clearly seen.

Very Short Answer Type Questions

Question 12.
lt was Paheli’s birthday. Her grandmother gave her two gifts made of metals, one old dull silver spoon and a pair of lustrous gold earrings. She was surprised to see the difference in the appearance of the two metals. Can you explain the reason for this difference?
Solution:
Gold is a noble metal it does not react with the gases present in the atmosphere. Silver reacts with some gases like hydrogen sulphide and loses its shine in moist air.

Question 13.
Mixtures of red chilli powder in water, butter in water, petrol in water, and honey in water were given to Radha, Sudha, Sofia and Raveena, respectively. Whose mixture is in solution form?
Solution:
Honey and water are miscible in each other hence a solution will be formed when honey is mixed with water. Raveena will get the mixture in solution form.

Question 14.
On a bright sunny day, Shikha was playing hide and seek with her brother. She hid herself behind a glass door. Do you think her brother will be able to locate her. If yes, why? If no, why not?
Solution:
Yes, because glass door is translucent hence Shikha can be located.

Question 15.
Take a small cotton ball and place it in a tumbler/ bowl filled with water. Observe it for atleast 10 minutes. Will it float or sink in water and why?
Solution:
Initially the cotton ball floats on water. Slowly it absorbs water, becomes heavy and sinks in water.

Question 16.
Which among the following materials would you identify as soft materials and why? Ice, rubber band, leaf, eraser, pencil, pearl, a piece of wooden board, cooked rice, pulses and fresh chapati.
Solution:
Rubber band, leaf, eraser, cooked rice and fresh chapati are soft materials because they can be scratched or compressed easily.

Question 17.
You are provided with the following materials – turmeric, honey, mustard oil, water, glucose, rice flour, groundnut oil.
Make any three pairs of substances where one substance is soluble in the other and any three pairs of substances where one substance remains insoluble in the other substances.
Solution:
I. Soluble pairs
(i) Honey – water
(ii) Glucose – water
(iii) Mustard oil – groundnut oil
II. Insoluble pairs
(i) Turmeric – water
(ii) Mustard oil-water
(iii) Rice flour – water

Question 18.
During summer holidays, a group of children collected a lump of salt, green grass, broken glass piece, a small thermocol box, pen, iron nail, glass marbles, hair, naphthalene ball, a piece of sugar candy (mishri) and tried to group them on the basis of properties given in table 4.1 below. Help them in filling the table.

Name of the material Appearance
(Hard/Soft)		 Transparency
(Transparent/
Translucent/Opaque)		 Floats/ Sinks in water Soluble/ Insoluble in water

Solution:

Name of
the
material

Appe­arance(Hard/Soft)

 Transparency(Transparent
/Translucent/Opaque)		 Floats
/Sinks
in water		 Soluble/ Insoluble in water
Lump of salt Hard Opaque Sinks Soluble
Green
grass		 Soft Opaque Floats Insoluble
Broken
glass
piece		 Hard Transparent Sinks Insoluble
Therm- ocol box Soft Opaque Floats Insoluble
Pen Hard Opaque Floats Insoluble
Iron nail Hard Opaque Sinks Insoluble
Glass
marbles		 Hard Transparent Sinks Insoluble
Hair Hard Opaque Floats Insoluble
Naph­
thalene
ball		 Hard Opaque Floats Insoluble
A piece of sugar candy Hard Opaque Sinks Soluble

Question 19.
Arrange the jumbled words to arrive at the appropriate names of materials and also write two uses of each.
(a) milaunuim
(b) tcaslpi
(c) soekrnee
(d) gavnier
Solution:
(a) Aluminium – Foil in food wraps, in making aircraft, etc.
(b) Plastic – Buckets/pencil box, etc.
(c) Kerosene – Fuel, solvent, etc.
(d) Vinegar – Preservative, food ingredients, etc.

Question 20.
Match the objects given in column I with the materials given in column II.

Column 1 Column II
(a) Surgical
instruments		 (i) Plastic
(b) Newspaper (ii) Animal product
(c) Electrical switches (iii) Steel
(d) Wool (iv) Plant
product

Solution:
(a) – (iii)
(b) – (iv)
(c) – (i)
(d) – (ii)
Surgical instruments – Steel (rust free)
Newspaper – Plant product (paper)
Electrical switches – Plastic (insulator)
Wool – Animal product (sheep)

Question 21.
Pick five objects from the word box given as Fig. 4.1 which are opaque and would sink in water.

O S T P L E
A T L E E R
C O I N A A
O N K C F S
A E E I W E
L L Y L R R

Fig.:4.1
Solution:
1. Stone, 2. Coin, 3. Coal, 4. Pen, 5. Eraser

Long Answer Type Questions

Question 22.
Chalk, iron nail, wood, aluminium, candle, cotton usually look different from each other. Give some properties by which we can prove that these materials are different.
Solution:
Chalk – Hard, rough, non-lustrous
Wood – Hard, rough, non-lustrous
Aluminium – Hard, smooth, lustrous
Candle – Hard, smooth, non-lustrous
Cotton – Soft, smooth, non-lustrous
Iron nail – Hard, smooth, lustrous

Question 23.
Why do you think oxygen dissolved in water is important for the survival of aquatic animals and plants?
Solution:
The oxygen which is dissolved in water is used’by animals for breathing and used by plants for breathing and photosynthesis.

Question 24.
Differentiate among opaque, translucent and transparent materials, giving one example of each.
Solution:
Opaque substances are those substances through which objects cannot be seen, e.g., wood, stone.
Translucent substances are those substances through which objects can be seen but not clearly, e.g., oiled paper, frosted glass. Transparent substances are those substances through which objects can be seen clearly e.g., glass, clear water.

Question 25.
Sugar, salt, mustard oil, sand, sawdust, honey, chalk powder, petals of flower, soil, copper sulphate crystals, glucose, wheat flour are some substances given to Paheli. She wants to know whether these substances are soluble in water or not. Help her in identifying soluble and insoluble substances in water.
Solution:
Sugar – Soluble in water
Salt – Soluble in water
Mustard oil – Insoluble in water
Sand – Insoluble in water
Sawdust – Insoluble in water
Honey – Soluble in water
Chalk powder – Insoluble in water
Petals of flower – Insoluble in water
Soil – Insoluble in water
Copper sulphate crystals – Soluble in water
Glucose – Soluble in water
Wheat flour – Insoluble in water

NCERT Exemplar Class 6 Science Solutions

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CBSE Previous Year Question Paper Class 10 Hindi

Download CBSE Hindi Sample Question Paper Class 10 PDF (Previous year papers) to understand the pattern of questions asked in the board exam. Know about the important topics to be prepared for CBSE Class 10 Hindi board exam and Score More marks. Here we have given Previous year Hindi question paper class 10.

CBSE Hindi Question Paper Class 10

 Description Details
Board Central Board of Secondary Education
Class Class 10
Subject Hindi A and Hindi B
Number of Previous Year Question Papers 3 Papers
Category CBSE Sample Papers
Official Website cbse.nic.in

Previous Year Question Papers for Class 10 Hindi

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To Prepare 2-Naphthol Aniline or Phenyl-azo-β-Naphtholdye

To Prepare 2-Naphthol Aniline or Phenyl-azo-β-Naphtholdye 

Theory
2-Naphthol aniline dye or Phenyl-azo-β-naphthol is an orange-red dye. It belongs to a large class of azo-compounds, all of which contain the characteristic grouping
to-prepare-2-naphthol-aniline-or-phenyl-azo-β-naphtholdye-1
Azo compounds are all coloured compounds. For the preparation of this dye, aniline is diazotised and then diazonium salt thus obtained is subjected to coupling reaction with 2-naphthol.
to-prepare-2-naphthol-aniline-or-phenyl-azo-β-naphtholdye-2

Apparatus
One 100 mL conical flask, one 100 mL beaker, one 250 mL beaker, ice-bath, glass-rod, buchner funnel, water pump.

Chemicals Required
Aniline = 4.5 ml
Sodium nitrite = 4g
2-Naphthol = 7 g
Cone, hydrochloric acid = 10 ml
Glacial acetic acid = 40 ml

Procedure

  1. Take a 100 ml conical flask and add 4.5 ml of aniline, 10 ml of cone. HCl and 20 ml of water. Cool this solution to 5°C by placing the conical flask in a trough containing ice- cold water.
  2. In a 100 ml beaker dissolve 4 g of sodium nitrite in 20 ml of water and cool this solution also to 5°C.
  3.  Now slowly add sodium nitrite solution to the solution of aniline in cone. HCl.
  4. Dissolve 7.0 g of 2-naphthol in 60 ml of 10% NaOH solution taken in a 250 ml beaker and cool this solution to 5°C by placing in an ice bath. Some crushed ice may be added directly to fecilitate cooling.
  5. Now add the diazotised solution very slowly to the naphthol solution with constant stirring. The mixed solutions immediately develop a red colour and the phenyl-azo-β- naphthol rapidly separates as orange-red crystals.
  6. When the addition of diazo solution is complete, allow the mixture to stand in ice-salt mixture for 30 minutes, with occasional stirring. Filter the solution through a buchner funnel under suction from the pump. Wash the phenyl-azo-β-naphthol with water and dry the crystals obtained by pressing between the folds of filter paper.
  7. Recrystallise the product from glacial acetic acid. Filter the crystals obtained at the pump. Wash with a few ml of ethanol to remove acetic acid. Phenyl-azo-β-naphthol is obtained as orange-red crystals. Expected yield is 3 g and melting point is 133°C.

Result
Weight of phenyl-azo-β-naphthol obtained as orange-red crystals = …….g.
Melting point of phenyl-azo-β-naphthol is…….°C.

Precautions

  1. The solution of the aniline hydrochloride should be cooled to 5°C, and this temperature should be maintained throughout the addition of the sodium nitrite solution.
  2. Addition of sodium nitrite should be very slow because the reaction is exothermic and may cause the temperature to rise.
  3. Always add diazonium chloride solution to β-naphthol solution for dye formation and not vice-versa.

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