Question

When magnesium ammonium phosphate is heated, it is converted to:
A.Magnesium pyrophosphate
B.Magnesium oxide
C.Magnesium phosphate
D.Magnesium nitride

Answer 1

Reagents: those compounds which react with each other to form the other compounds, are known as reagents. They are present on the left side of the reaction.
Products: The compounds formed by the reaction of reagents, are known as products. They are present on the right side of the reaction.

Complete step by step solution:
First of all we will talk about reagents and products.
Reagents: those compounds which react with each other to form the other compounds, are known as reagents. They are present on the left side of the reaction.
Products: The compounds formed by the reaction of reagents, are known as products. They are present on the right side of the reaction.
Balanced reaction: The reaction in which the number of all atoms on both sides i.e. on the reactant side and on the product side are same, are known as balanced reactions.
Limiting reagent: The reagent which is completely consumed during the reaction, is known as limiting reagent.
Excess reagent: The reagent which is left after the reaction, is known as excess reagent.
Oxidation number: It is also known as oxidation state. It is defined as the number of electrons which are gained or loss of an atom or ion to form a molecule, is known as oxidation number. Oxidation number of any element is calculated as the sum of the oxidation number of all atoms present in the molecule is equal to zero in case of neutral molecule or the given charge in case of ion.
Magnesium pyrophosphate: It is defined as the molecule having the molecular formula $M{g_2}{P_2}{O_7}$.
Magnesium oxide: It is defined as the molecule having the molecular formula $MgO$.
Magnesium phosphate: It is defined as the molecule having molecular formula $(Mg{({H_2}P{O_4})_2})x{H_2}O$.
Magnesium nitride: It is defined as the molecule having the molecular formula $M{g_3}{N_2}$.
When magnesium ammonium phosphate i.e. $N{H_4}MgP{O_4}.6{H_2}O$, is heated then it first gives amorphous phase product and then crystalline magnesium pyrophosphate as a product. The reaction is as follows:
$2N{H_4}MgP{O_4}.6{H_2}O \to M{g_2}{P_2}{O_7} + 2N{H_3} + 7{H_2}O$.
Hence magnesium pyrophosphate is formed as a product.

So option A is correct.

Note: Amorphous compounds: They are not arranged in repeating order i.e. they are randomly arranged. They do not have regular arrangement of atoms so they do not have definite shape i.e. irregular in shape.
Crystalline compounds: They are arranged in repeating order. They have regular arrangement of atoms so they have definite shape.