Measurements show that the energy of a mixture of gaseous reactants decreases by during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that of work is done on the mixture during the reaction. Calculate the change in enthalpy of the gas mixture during the reaction. Be sure your answer has the correct number of significant digits. Is the reaction exothermic or endothermic

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QUESTION;

Understanding the enthalpy definition=

Measurements show that the enthalpy of a mixture of gaseous reactants increases by 125.kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that -71.kJ of work is done on the mixture during the reaction. Calculate the change in enthalpy of the gas mixture during the reaction and determine if the reaction is endothermic or exothermic.

ANSWER: The change in enthalpy of the gas mixture during the reaction is 54.kJ

The reaction is endothermic.

EXPLANATION: Enthalpy is the heat change in a system.

To calculate enthalpy we use the formula below;

H = E + PV

H is the enthalpy

E is the energy used in the reaction

PV is the product of pressure and volume which is refered to as the work done in the system

Using the equation above

H = 125 + (-71) = 54.kJ

An endothermic reaction is a type of reaction where heat is gained by the system from it's environment, and the enthalpy of such system is positive. While an Exothermic reaction is a type of reaction where heat is lost by the system to it's environment, and the enthalpy of such system is negative.

Because our enthalpy value is positive, this is an endothermic reaction.

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.