Chemistry MCQs for NEET — Practice Questions with Answers

The molar heat of neutralization is the heat change that occurs when one mole of water is formed from the reaction of an acid and a base. For strong acids and bases like NaOH and HCl, the molar heat of neutralization is typically constant at about -57.1 kJ/mol because they fully dissociate in water. Thus, the molar neutralization heat is equal for strong acid and base combinations.

An endothermic reaction is one that absorbs energy from its surroundings, typically in the form of heat. If the enthalpy of B is greater than that of A, it means the reaction $A ightarrow B$ requires an input of energy, making it an endothermic reaction.

Kerosene has a higher calorific value compared to charcoal, wood, and dung. Calorific value is the amount of energy released during the combustion of a substance. Kerosene, being a refined petroleum product, has a higher energy content per kilogram compared to the other options.

The heat of neutralization is defined as the heat set free when one gram equivalent of an acid is neutralized by one gram equivalent of a base in dilute solution at a stated temperature. This definition specifically considers the neutralization reaction between acid and base in molar equivalents.

Compounds with a high heat of formation are less stable because they are in an energy-rich state which leads to instability. High heat of formation indicates that a lot of energy is stored within the compound, making it prone to releasing energy and thus being less stable.

A Beckmann thermometer is specifically designed to measure small differences in temperature, often in the range of 0.01°C to 5°C. This makes it suitable for measuring low temperatures with high precision.

The calorific value of fat is higher than that of carbohydrates and protein. This is because fats contain long chains of hydrocarbons which, when oxidized, release more energy compared to carbohydrates and proteins. Carbohydrates and proteins have approximately 4 kcal/g, while fats have about 9 kcal/g.

The decomposition of $N_2O_5$ to $N_2O$ and $O_2$ is accompanied by an increase in entropy. This is because the decomposition reaction results in more molecules being produced (more moles of gas). In general, reactions that produce more gas molecules tend to have an increase in entropy.