Answer : The mathematical equation used when solving calorimetry problems is:

Explanation :
Calorimetry : It is determining the changes in the energy of a system by measuring the heat transferred with surroundings.
Formula used :

where,
c = specific heat capacity of calorimeter
m = mass of a substance
q = heat required
= change in temperature of substance
1.a- sodium(Na) b-nickel(Ni) c-iron (Fe)
Answer:
First-order with respect to hydrogen.
Explanation:
Hello!
In this case, considering that the rate law of this reaction can be expressed via:

If we want to know m, the order of reaction with respect to hydrogen, we need to relate the experiments 1 and 3 in order to get rid of the pressure of ICl:

Thus, we plug in the given rates, and pressures to get:

So we can cancel wout k and 325^n:

Next we solve for m, the order of reaction with respect to hydrogen:

It means it is first-order with respect to hydrogen.
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