1- If the following processes take place at constant pressure, which will be exo

Question

1- If the following processes take place at constant pressure, which will be exothermic and which will be endothermic?

I. Gasoline burns.

II. Two solids at room temperature are mixed and the temperature of the mixture decreases to 15 °C   

( please expline why did you choose your anwser)

2-What is the correct ranking of the electrostatic potential energy of the following systems, starting with the one with the lowest energy?

I an electron that is 2.8 nm from a +2 cation

II an electron that is 2.8 nm from a –2 anion

III an electron that is 2.8 nm from a proton A. I < III < II

B. I = II < III

C. II < III < I

D. II < I < III

E. III < II = I

(please explain why did you choose your answer)

Explanation / Answer

Answer – 1) We are given the process and need to determine where they are exothermic or endothermic.

When gasoline burn there is energy gets released and we know, when process is releasing the energy then it is an exothermic process.

When two solids at room temperature are mixed and the temperature of the mixture decreases to 15 °C , means energy gets absorbed and we know when process is absorbing the energy then it is an endothermic process.

2) We know the electrical potential energy per unit of charge. This is the depending on the amount of charge you are moving. We know as we charge positive towards electric field there is positive work done and the electrical potential energy is more, so the an electron that is 2.8 nm from a +2 cation has more energy and an electron that is 2.8 nm from a –2 anion has less. So answer is C. II < III < I

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.