Answer : The enthalpy of the given reaction will be, -1048.6 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
The main reaction is:

The intermediate balanced chemical reactions are:
(1)

(2)

(3)

(4)

(5)

Now reversing reaction 2, multiplying reaction 3 by 4, reversing reaction 1 and multiplying by 2, reversing reaction 5 and multiplying by 2 and then adding all the equations, we get :
(1)

(2)

(3)

(4)

(5)

The expression for enthalpy of main reaction will be:



Therefore, the enthalpy of the given reaction will be, -1048.6 kJ
The third one because temperature is being used, so a meter stick wouldn’t make sense. You aren’t measuring the length of anything physically. A stopwatch measures time, which is what they are showing in the chart, so the third one is the only one that makes sense.
Hey did you ever find the answers to this?
<span>An independent variable is a variable that is not affected in the experiment. It is what experimenter controls. Here, the concentration of salt is the independent variable.
On the other side, a dependent variable is called dependent because it depends on the independent variables. It is what is affected and observed during the experiment. Here, the freezing point of water is affected and, thus, it is the dependent variable.
A controlled variable is a variable that must remain unchanged (must be constant) during the experiment so that the effect on the dependent variable depends only on the independent variable. Here, the volume of water must be constant, so it is the controlled variable.
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