The question asks for the mass ratio of hydrogen to oxygen in water (Hâ‚‚O). This can be determined by using the atomic masses of hydrogen and oxygen and the chemical formula of water.
Correct Option: B) H : O = 1 : 8 by mass (2 g of H for every 16 g of O)
To determine the mass ratio of carbon to oxygen in carbon dioxide (\(\text{CO}_2\)), we need to use the atomic masses of carbon and oxygen. The formula for carbon dioxide indicates one carbon atom and two oxygen atoms.
B) C : O = 3 : 8 by mass (12 g carbon for every 32 g oxygen). This option correctly states the mass ratio as \(3:8\) and provides the unsimplified masses \(12\) g carbon for \(32\) g oxygen, which is consistent with our calculation.
The question asks to identify a scenario that would violate the Law of Definite Proportions. This law states that a given chemical compound always contains its component elements in fixed ratio by mass, regardless of its source or method of preparation. We need to find an option where the composition of a specific compound varies.
Therefore, the scenario described in Option A would violate the Law of Definite Proportions.
A) If copper sulphate prepared from copper mines in India had a different Cu:S:O ratio than copper sulphate prepared from Australian copper. This scenario directly contradicts the Law of Definite Proportions, which states that a pure chemical compound like copper sulphate (\(CuSO_4\)) must have a fixed elemental composition (Cu:S:O ratio by mass) regardless of its source or method of preparation.
The question asks to identify the scientist who proposed the Law of Multiple Proportions and the year of its proposal. This requires knowledge of fundamental laws of chemistry and their historical context.
Correct Option: B) John Dalton, 1803
The question asks for the correct statement of the Law of Multiple Proportions. This law is one of the fundamental laws of chemical combination, proposed by John Dalton. We need to recall its definition and compare it with the given options.
B) When two elements form more than one compound, the masses of one element that combine with a fixed mass of the other element bear a simple whole number ratio to each other.
The Law of Multiple Proportions states that if two elements can combine to form more than one compound, then the ratios of the masses of the second element that combine with a fixed mass of the first element are ratios of small whole numbers. We need to identify the option that correctly demonstrates this principle.
Correct Option: A) Carbon and oxygen form two compounds: CO (12 g C with 16 g O) and COâ‚‚ (12 g C with 32 g O); ratio of O masses = 16:32 = 1:2. This option correctly demonstrates that when a fixed mass of one element (carbon) combines with different masses of another element (oxygen) to form different compounds, these different masses of the second element bear a simple whole-number ratio to one another.