Chemistry, 20.10.2019 15:50 mardell2587

Which of the following is an exothermic reaction?

a. dissolving ammonium nitrate in water to cool the water

b. condensation

c. melting ice

d. dissolving sugar in water

Answers: 3

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Answers

Answer from: mags1467

I think the correct answer among the choices listed above is option B. Condensation is a process which an exothermic one. Exothermic processes involves heat being released to the environment which is evident in the process of condensation.

Answer from: angie1129

The correct answer is Option B.

Explanation:

Exothermic reaction is defined as the reaction in which heat is released to the surroundings from the system. The total enthalpy change of the reaction comes out to be negative.

Endothermic reactions are the ones where heat is absorbed from the surrounding by the system. The total enthalpy change of this reaction comes out to be positive.

For the given options:

Option A: When ammonium nitrate is added in the water to cool it, the heat is getting absorbed. Then only the water is getting cooled. Thus, it is considered as an endothermic reaction.

Option B: Condensation is a process in which gaseous state changes into liquid state. The temperature of the system gets reduced and thus heat is getting released in this process. Thus, it is considered as an exothermic reaction.

Option C: Melting is a physical process in which solid state is converted into liquid state. To do this, heat must be provided to separate the particles from one another. Thus, it is considered as an endothermic reaction.

Option D: When sugar is dissolved in water, heat is provided so that it gets completely dissolved. Thus, it is considered as an endothermic reaction.

Hence, the correct answer is Option B.

Answer from: Quest

Ithink the answer is a or d.

Answer from: Quest

For cyclohexane compounds drawn in a chair conformation: -axial bonds are vertical -equatorial bonds are parallel to two bonds within the ring. thus, as i assume the chair conformation is drawn: -the x group is in an axial position, as are the five other vertical bonds. -three axial bonds are on the top face of the ring -the other three axial bonds are on the bottom face the position of the second substituent on each ring carbon is equatorial. gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other. drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1. click this link and watch some academic videos that may you more understand the topic