Chemistry
Grade-8
Easy
Question
The true statement among the following is
- In a pure water, the ratio of mass of hydrogen to oxygen is 1 : 8 but it changes to 1 : 9 when the water is sea water.
- The atomic mass of magnesium is 28 grams.
- If an ice cube weighing 50 grams melts, then it should produce also produce at least 60 grams of water.
- According to law of constant proportion, it does not matter how the compound is formed.
Hint:
The ratio of any substance remains the same no matter what.
The correct answer is: According to law of constant proportion, it does not matter how the compound is formed.
The law of constant proportions states that a compound is composed of a constant mass proportion of elements. This means that regardless of the source, a pure sample of a compound will always consist of the same elements present in the same mass ratios. For example, pure water always contains hydrogen and oxygen in a fixed mass ratio (1 gram of water is approximately 0.11 grams of hydrogen and 0.88 grams of oxygen, a ratio of 1:8).
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