=》There element use r different and in first it is ammonium hydroxide and second is magnesium oxide....or .....=》In first reaction we are adding hydrogen but In second we are adding oxygen because of this they are different.

1. Reactants

The first major difference between the two reactions is the reactants involved. In the reaction NH3(aq) + H2O, ammonia (NH3) and water (H2O) are the reactants. On the other hand, in the reaction 2Mg + O2, magnesium (Mg) and oxygen (O2) are the reactants.

2. Products

The second difference lies in the products formed after the reaction. In the reaction NH3(aq) + H2O, the products formed are ammonium hydroxide (NH4OH). On the other hand, in the reaction 2Mg + O2, the products formed are magnesium oxide (MgO).

3. Type of Reaction

Another difference between the two reactions is the type of reaction they belong to. The reaction NH3(aq) + H2O → NH4OH is an example of a neutralization reaction, where an acid (NH3) reacts with a base (H2O) to form a salt (NH4OH). On the other hand, the reaction 2Mg + O2 → 2MgO is an example of a combustion reaction, where a substance (magnesium) reacts with oxygen to produce an oxide.

4. Balanced Equations

The balanced equations for the two reactions further highlight their differences. The balanced equation for the reaction NH3(aq) + H2O → NH4OH is:

NH3(aq) + H2O → NH4OH

In this equation, there is a 1:1 ratio between NH3 and NH4OH.

On the other hand, the balanced equation for the reaction 2Mg + O2 → 2MgO is:

2Mg + O2 → 2MgO

In this equation, there is a 2:1 ratio between Mg and MgO, indicating that two moles of magnesium react with one mole of oxygen to produce two moles of magnesium oxide.

5. Physical State

The physical state of the reactants and products is also different in the two reactions. In the reaction NH3(aq) + H2O, both ammonia and water are in the liquid state. However, in the reaction 2Mg + O2, magnesium is in the solid state, while oxygen is in the gaseous state. The product magnesium oxide is in the solid state.

6. Stoichiometry

The stoichiometry of the reactions is another aspect that sets them apart. In the reaction NH3(aq) + H2O → NH4OH, one molecule of ammonia reacts with one molecule of water to produce one molecule of ammonium hydroxide. On the other hand, in the reaction 2Mg + O2 → 2MgO, two atoms of magnesium react with one molecule of oxygen to form two molecules of magnesium oxide.

Overall, these two reactions differ in terms of their reactants, products, type of reaction, balanced equations, physical state of reactants and products, and stoichiometry. Understanding these differences helps us appreciate the diverse nature of chemical reactions and how different elements and compounds can interact to form new substances.