NCERT Solutions for Class 4 EVS Chapter 27 Chuskit Goes To School

NCERT Solutions for Class 4 EVS Chapter 27 Chuskit Goes To School

NCERT PAGE NUMBER 212
1. How do you go to school?
Ans. I go to school on bicycle.

2. Find out where Ladakh is. What kind of a place is it?
Ans. Ladakh is in Kashmir. It is the highest plateau of the Indian state. It is situated at a great height of 3000 m. It is a very cold place.

NCERT PAGE NUMBER 212-213
Chuskit’s Chair
1. What are the things that you enjoy doing in school?
Ans. I enjoy learning and also playing in school.

2. Do you like going to school?
Ans. Yes. I like to go to school.

3. Would you like it if you never could go to school?
Ans. No, I cannot even imagine of not going to school.

NCERT PAGE NUMBER 215
Talk About It
1. Who all helped Chuskit to reach school?
Ans. Abdul, Headmaster, teachers and children of the school helped Chuskit in reaching school.

2. If you were Abdul what would you have done?
Ans. I would have done the same thing what Abdul did.

3. At last, Chuskit could reach school. Do you think that she may face some difficulties in school? What kind of difficulties?
Ans. Yes, I think she would have to face problems such as, the problem in moving over stairs etc. She will not be able to play like normal children.

4. If you were Chuskit’s friend, how would you help her?
Ans. I would help her in going around and would support her in all possible ways.

5. Do you have ramps in your school on which a wheelchair can move?
Ans. No, there is no such ramp. However, on verandah and the roads around the garden in the school, a wheelchair can move.

6. Do you know any child near your house who cannot go to school because of some difficulty?
Ans. Yes, one of the children who lives near my house does not go to school because of his blindness.

7. Would you like to help such a child?
Ans. Yes, I would like to help such a child.

8. How will you help?
Ans. I would like to convince his parents to send him to the school for the blind. I would read out lessons and stories for him.

9. Look at the buildings around your house. Can a wheelchair go inside the building?
Ans. Yes, a wheelchair can go inside the building.
Let Us Do
10. Draw pictures of a ramp and a wheelchair in your notebook.
Ans.
NCERT Solutions for Class 4 EVS Chapter 27 Chuskit Goes To School Page 215 Q10
11. Why not make your own bridge? For this, use material that you can find around you-Ice cream sticks, plastic spoons, small sticks, rope, string etc.
Your friends can also make bridge.
Ans. Do it yourself.
NCERT Solutions for Class 4 EVS Chapter 27 Chuskit Goes To School Page 215 Q11
12. In a group of friends make a model showing fields, rivers, mountains, roads, and railway tracks, etc.
You can use clay, sand, pebbles, twigs, leaves. Place your bridges at different positions on this model.
Ans. Do it yourself.

13. Help Chuskit to reach school
NCERT Solutions for Class 4 EVS Chapter 27 Chuskit Goes To School Page 215 Q13
Ans.
NCERT Solutions for Class 4 EVS Chapter 27 Chuskit Goes To School Page 215 Q13.1

NCERT SolutionsEVSMathsEnglishHindiParyavarana Adhyayan

Determine volumetrically the number of water molecules of crystallisation in washing soda

Determine volumetrically, the value of ‘n’ i.e., the number of water molecules of crystallisation in washing soda \(Na_{2}CO_{3}.nH_{2}O\), 7.0 g of which have been dissolved per litre of the given solution. Provided \(\frac{M}{10} HCl\)

Chemical Equation:

quantitative-estimation-volumetric-analysis-27

Indicator. Methyl orange.
End Point. Yellow to light pink (Acid in burette)

Procedure

  1. Rinse and fill the burette with the standard HCl solution.
  2. Rinse the pipette with the sodium carbonate solution and pipette out 20 ml of this solution in the titration flask.
  3. Add 2-3 drops of methyl orange indicator to the titration flask. The colour of the solution becomes yellow.
  4. Note the initial reading of the burette and run acid solution slowly in the titration flask till the solution becomes light pink.
  5. Note the final reading of the burette and find out the volume of acid used.
  6. Repeat the procedure 4-5 times to get a set of at least three concordant readings.

Observations

Molarity of given HCl solution = \(\frac{M}{10}\)

Volume of sodium carbonate solution taken for each titration = 20.0 ml

S.No. Initial reading of the burette Final reading of the burette Volume of the acid solution used
1. —  _ — ml
2. — — — ml
3. — — — ml
4. — — — ml

Concordant volume = x ml (say).

Calculations

The molarity of standard HCl = 0.1 M

Since in the balanced equation two moles of HC1 react with one mole of Na2C03.nH20.

\(\frac { { M }_{ HCl }\times V_{ HCl } }{ { M }_{ { Na }_{ 2 }{ CO }_{ 3 } }\times { V }_{ { Na }_{ 2 }{ CO }_{ 3 } } }==\frac { 2 }{ 1 } \)

 

\(\frac { 0.1\times x }{ { M }_{ { Na }_{ 2 }{ CO }_{ 3 } }\times 20.0 } =\frac { 2 }{ 1 } \)

 

\({ M }_{ { Na }_{ 2 }{ CO }_{ 3 } }=\frac { 1\times x\times 0.1 }{ 2\times 20.0 } =\frac { x }{ 400 } \)

 

\({ M }_{ { Na }_{ 2 }{ CO }_{ 3 } }=\frac { Streanth\quad per\quad litre }{ Molar\quad mass\quad of\quad { Na }_{ 2 }{ CO }_{ 3 }.n{ H }_{ 2 }O } \)

 

\(Molar\quad mass\quad of\quad { Na }_{ 2 }{ CO }_{ 3 }.n{ H }_{ 2 }O=\frac { Streanth\quad per\quad litre }{ { M }_{ { Na }_{ 2 }{ CO }_{ 3 } } } \)

 

\(=\frac { 7.0 }{ \frac { x }{ 400 }  } \quad g{ mol }^{ -1 }\)

 

But molar mass of hydrated sodium carbonate = (106 + 18n) g mol-1

therefore,

\(\frac { 7.0 }{ \frac { x }{ 400 }  } =108+18n\)

Knowing the titre value, x, the value of n can be calculated.

Result

The number of the molecules of water of crystallisation in washing soda is …..
Note. The result is expressed as nearest whole number. The value of n is 10 in this case.

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