Concept explainers
Two samples of a compound containing elements A and B are decomposed. The first sample produced15 g of A and 35 g of B. The second sample produced25 g of A and what mass of B?
a) 11 g
b) 58 g
c) 21 g
d) 45 g
Interpretation: The mass of element B present in the second sample is to be determined.
Concept Introduction: Joseph Proust in 1797, gave a law of definite proportion. According to this law, all the samples of a compound contains same proportion of their constituent elements regardless of whatever the source of the compound.
Answer to Problem 1SAQ
Correct answer: The mass of B produced by sample 2 is
Explanation of Solution
Justify reasons for the correct statement:
In accordance with the law of definite proportions, the mass of constituent elements in all the samples of a given compound are in the same proportion. This means, in first sample the total mass of a compound i.e.
Thus,
As the ratio of the constituent elements in a compound remains same. Therefore, this ratio is used to calculate the mass of B. Calculate the mass of B as follows:
Rearrange the above expression as follows:
Justify reasons for the correct statement:
Option (a) is incorrect because according to the above calculations, the mass of element B cannot be obtained as
Option (c) is incorrect because according to the above calculations, the mass of element B cannot be obtained as
Option (d) is incorrect because according to the above calculations, the mass of element B cannot be obtained as
The correct answer is option (b).
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