A student made a sketch of a potential energy diagram to represent an endothermic reaction. Explain, using complete sentences, why the diagram made by the student is correct or incorrect. Be sure to also explain what the values of X and Y represent. (10 points)

Incorrect

Explanation:

X is the reactants

Y is the products

In an endothermic reaction where energy is absorbed, the enthalpy the products (Y) is always higher than the enthalpy of the reactants (X).

Enthalpy change (∆H) = products (Y) - Reactants (X)

For an endothermic reaction, the ∆H value should be positive.

Enthalpy change

The diagram sketched by the students shows the opposite. The diagram shows that the enthalpy of the products (Y) is lower than the enthalpy of the reactants (X). This will give a negative value of ∆H.

It represents an exothermic reaction rather than endothermic.

Therefore, the student is incorrect.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.