How Does Changing Cobalt Chloride and Water Amounts Affect Reaction Temperature?

[jsmith613]

Homework Statement

say we were hydrating Cobalt chloride crystals

why would
(i) more cobalt chloride
(iii) less water
result in a GREATER temperature change of reaction>
thanks

Homework Equations

The Attempt at a Solution

for ii I have used Q = mcΔt and on re-arranging to for Δt Q/mc is GREATER for a smaller mass of water.

for i I am less sure. I thought as follows: heat change is per mole of substance. If we have more moles the heat change will be greater.
I am not so sure on this though - please could someone confirm if I am correct for both i and ii

 

[nate808]

.

it is important to consider the principles of stoichiometry when discussing the temperature change of a reaction. In the case of hydrating Cobalt chloride crystals, the reaction is exothermic, meaning it releases heat. This heat is a result of the breaking of bonds between the cobalt ions and water molecules, and the formation of new bonds between the hydrated cobalt ions and water molecules.

In regards to the first question (i), adding more cobalt chloride to the reaction will result in a greater temperature change because there are more moles of cobalt ions available to form bonds with water molecules. This means that more energy will be released in the reaction, resulting in a greater temperature change.

For the second question (ii), using less water will also result in a greater temperature change. This is because the amount of heat released in the reaction is divided by the mass of water used. Therefore, using less water will result in a higher temperature change because there is less mass to divide the heat by.

It is important to note that the concentration of the cobalt chloride solution also plays a role in the temperature change of the reaction. A higher concentration of cobalt chloride will result in a greater temperature change, as there are more cobalt ions available to form bonds with water molecules.

In conclusion, both adding more cobalt chloride and using less water in the reaction will result in a greater temperature change. This is due to the principles of stoichiometry and the relationship between the amount of reactants and the amount of heat released in the reaction.