B and D is out. It cant be A because heat of combustion is substance not compound. So the answer is D.
The law of definite proportions would state that a hydrate always contain exactly the same proportion of salt and water by mass.
strictly speaking, the law of definite proportion states that a compound always
contains exactly the same proportion of elements by mass.
But the law is often applied to groupings of elements in compound.
Hydrates are salt that have a certain amount of water asa part of their structure.
The water is chemically combined with the compound in a definite ratio.
Bronsted - Lowry acid in the given reaction is NH₄, as it gives H⁺ ion.
<h3>What is Bronsted - Lowry acid?</h3>
According to the theory of Bronsted - Lowry, acids are those substances which gives H⁺ ion or proton in the aqueous medium.
Given chemical reaction is :
NH₄ + HPO₄²⁻ → NH₃ + H₂PO₄⁻
In the above reaction NH₄ is the Bronsted - Lowry acid as it gives H⁺ ion in the reaction and changes to NH₃ which is the conjugate base of NH₄. Whereas HPO₄²⁻ is the Bronsted - Lowry base as it accepts the H⁺ ion to form H₂PO₄⁻ which is the conjugate acid of it.
Hence, option (1) is correct, i.e. NH₄ is the Bronsted - Lowry acid.
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