The initial temperature of the water in a constant-pressure calorimeter is 24°c. a reaction takes place in the calorimeter, and the temperature rises to 87°c. the calorimeter contains 367 g of water, which has a specific heat of 4.18 j/(g·°c). calculate the enthalpy change (δh) during this reaction

Answer : The enthalpy change during the reaction is 4.74 kJ/mole

Explanation :

First we have to calculate the heat released during the reaction.

where,

q = heat released = ?

= specific heat of water =

m = mass of water = 367 g

= final temperature of water =

= initial temperature of metal =

Now put all the given values in the above formula, we get:

Thus, the heat released during the reaction = 96.6 kJ

Now we have to calculate the enthalpy change during the reaction.

where,

= enthalpy change = ?

q = heat released = 96.6 kJ

n = number of moles water =

Therefore, the enthalpy change during the reaction is 4.74 kJ/mole

both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.