Most of the surface of the earth is covered with water and looks blue from space.
Answer: Correct options are as follows.
- salt is not chemically bonded to water.
- salt and water retain their own chemical properties.
Explanation:
When salt is dissolved in water then it means that it is a physical change as salt has completely dissociated into ions but they are not chemically combined to the water molecules.
As a result, both salt and water will retain their chemical properties.
For example, NaCl when dissolved in water will dissociate as follows.

Only the particles of salt have evenly distributed in water.
And, when a components of a salt chemically combine with another substance then it will form a new compound.
Therefore, we can conclude that salt dissolved in water is a solution, therefore:
- salt is not chemically bonded to water.
- salt and water retain their own chemical properties.
Answer:
Enthalpy of formation = -947.68KJ/mol
Explanation:
Enthalpy of formation is the heat change when one mole of a substance is formed from its element in its standard states and in standard conditions of temperature and pressure. it may be positive or negative, if positive, it is an endothermic reaction where the heat content of the product is greater than that of the reactants, and if negative, it is exothermic reaction - where the heat content of the reactants is greater than the products. the enthalpy of formation is measured in KiloJoule/Moles (KJ/Mole).
From the value of the enthalpy of formation of NaHCO3, it shows that the reaction is exothermic, that is the formation of NaHCO3 from its constituents elements. As such, the heat content of the reactants is greater than the products.
The step by step explanation is shown in the attachment.