Class 11 Chemistry - Chapter Some Basic Concepts of Chemistry NCERT Solutions | The following data are obtained when din
The following data are obtained when dinitrogen and dioxygen react together to form different compounds:
Mass of dinitrogen Mass of dioxygen
(i) 14 g 16 g
(ii) 14 g 32 g
(iii) 28 g 32 g
(iv) 28 g 80 g
(a) Which law of chemical combination is obeyed by the above experimental data?Give its statement.
(b) Fill in the blanks in the following conversions:
(i) 1 km = ...................... mm = ...................... pm
(ii) 1 mg = ...................... kg = ...................... ng
(iii) 1 mL = ...................... L = ...................... dm3
Let us fix 14 parts by weight of nitrogen as fixed weight.
Now let us calculate the weights of oxygen which combine with 14 parts by weight of nitrogen
|
Sno |
No of parts by weight of nitrogen |
No of parts by weight of oxygen |
14 parts of nitrogen as fixed weight |
No of parts by weight of oxygen which combine with 14 parts by weight of nitrogen |
|
1 |
14g |
16g |
14g |
16 |
|
2 |
14g |
32g |
14g |
32 |
|
3 |
28g |
32g |
14g |
32 |
|
4 |
28g |
80g |
14g |
80 |
(a) If we fix the mass of dinitrogen at 14 g, then the masses of dioxygen that will combine with the fixed mass of dinitrogen are 16 g, 32 g, 32 g, and 80 g.
The masses of dioxygen bear a whole number ratio of 1:2:2:5. Hence, the given experimental data obeys the law of multiple proportions.
This law was given by Dalton in 1804. The law states that if two elements combine to form 2 or more compound, then the weight of one element which combines a fixed weight of other element in these compounds,bears a simple whole number ratio by weight.
(b) (i) We know 1km=1000m
Or 1m = 1000 mm
Therefore 1km = 1000x 1000mm= 106 mm
1 km = 1 km ×
1 km = 1015 pm
Hence, 1 km = 106 mm = 1015 pm
(ii) We know 1kg = 1000mg
Or 1000mg= 1kg
Or 1mg= 1/1000* 1= 0.01 kg
1 mg = 1 mg × 
⇒ 1 mg = 106 ng
1 mg = 10–6 kg = 106 ng
(iii) We know 1000 ml=l L
Or 1ml=1/1000*1= 0.01L
1 mL = 1 cm3 = 1 cm3
⇒ 1 mL = 10–3 dm3
1 mL = 10–3 L = 10–3 dm3
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3 Comment(s) on this Question
Thx
No it is given in the question itself that the ratio of dioxygrn is 16, 32 , 32, 80 so the whole no ratio with dinitrogen is 1:2:2:5
If we fix the mass of dinitrogen at 14 g, then masses of dioxygen will be 16 g, 32 g, 16 g, & 40 g. Then the ratio becomes 1:2:1:2.5. Is there any mismatch or i have understood wrong. Kindly clarify With regards Krishnaraj
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