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Is Matter Around Us Pure

Question
CBSEENSC9006577

A body is vibrating 6000 times in one minute. If the velocity of sound in air is 360 m/s, find

(i) frequency of vibration in Hz, and

(ii) wavelength of the wave produced.

Solution
left parenthesis straight i right parenthesis space

No. space of space vibrations space equals space 6000

space space space space Time space taken space for space vibrations space equals space 1 space min space equals space 60 space straight s

space space space Frequency space space space straight v space equals space fraction numerator No. space of space vibrations over denominator Time space taken end fraction space equals space 6000 over 60 space equals space 100 space Hz.
left parenthesis ii right parenthesis space
V e l o c i t y space o f space t h e space w a v e comma space v space equals space 360 space straight m divided by straight s

Frequency comma space straight v space equals space 100 space Hz

space space U sin g space t h e space f o r m u l a comma space v space equals space vλ

space space therefore space Wavelength space space straight lambda space equals space v over straight v space equals 360 over 100 space equals space 3.6 space straight m.

Some More Questions From Is Matter Around Us Pure Chapter

Which separation techniques will you apply for the separation of the following?

Iron pins from sand.

Which separation techniques will you apply for the separation of the following?

Wheat grains from husk

Which separation techniques will you apply for the separation of the following?


Fine mud particles suspended in water.

Write the steps you would use for making tea. Use the words—solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.

Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).

Substance Dissolved

Temperature in K

283

293

313

333

353

Potassium nitrate

21

32

62

106

107

Sodium chloride

36

36

36

37

37

Potassium chloride

35

35

40

46

54

Ammonium chloride

24

37

41

55

66



What mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water at 313 K?

Pragya makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.

Substance Dissolved

Temperature in K

283

293

313

333

353

Potassium nitrate

21

32

62

106

107

Sodium chloride

36

36

36

37

37

Potassium chloride

35

35

40

46

54

Ammonium chloride

24

37

41

55

66



Find the solubility of each salt at 293 K. Which salt has the highest solubility at this temperature?

Substance Dissolved

Temperature in K

283

293

313

333

353

Potassium nitrate

21

32

62

106

107

Sodium chloride

36

36

36

37

37

Potassium chloride

35

35

40

46

54

Ammonium chloride

24

37

41

55

66



Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).

Substance Dissolved

Temperature in K

283

293

313

333

353

Potassium nitrate

21

32

62

106

107

Sodium chloride

36

36

36

37

37

Potassium chloride

35

35

40

46

54

Ammonium chloride

24

37

41

55

66


What is the effect of change of temperature on the solubility of a salt?

Explain the following giving examples:

Saturated solution

Explain the following giving examples:

Pure substance