Calculating Heat Produced in a Chemical Reaction

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In summary, the conversation discusses a chemical reaction involving OCl–, Cl–, H+, and Cl2, with a standard enthalpy change of -202 kJ mol–1. A solution containing 0.400 mol L–1 of both OCl– and Cl– was reacted with excess hydrochloric acid, resulting in a mass of 100 g. The question asks to find the heat produced in the reaction, assuming the temperature change and heat capacity of the mixture are negligible and equal to that of water. The solution involves determining the number of moles of Cl2 produced and using the given enthalpy change to calculate the heat produced.
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Homework Statement


OCl–(aq) + Cl–(aq) + 2H+(aq) Cl2(aq) + H2O ΔrH = -202 kJ mol–1
25.0mL of a solution 0.400mol L–1 in both OCl– and Cl– was reacted with excess hydrochloric acid. The mass of the solution after mixing was 100 g.
n(reaction) = 0.0100 mol

Find q(system) in joules.
Assume that the temperature change of the vessel in which the experiment is carried out is negligible
Assume that the heat capacity of the mixture is the same as the specific heat capacity of water (4.184 J g–1 K–1).

Homework Equations

I know somewhere you have to use the formula q = mcΔT but I am unsure what to do because there is no temperature in the question.

The Attempt at a Solution



I have tried multiplying the mass and temp change but I think i am wrong. Please help?
 
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It is not about q = mcΔT.

You are told how much heat is produced per mole of produced Cl2. How many moles were produced?
 

FAQ: Calculating Heat Produced in a Chemical Reaction

What is the definition of q(system)?

Q(system) refers to the amount of energy that is transferred into or out of a system during a process. It is typically measured in joules (J).

How do you find q(system) in joules?

To find q(system) in joules, you need to know the change in the internal energy of the system (ΔU) and the amount of work (W) done on or by the system. The formula for q(system) is q(system) = ΔU + W.

What is the significance of finding q(system) in joules?

Finding q(system) in joules allows scientists to quantify the amount of heat energy involved in a process. This can help in understanding and predicting the behavior of a system and its surroundings.

Can q(system) be negative?

Yes, q(system) can be negative if energy is transferred out of the system, usually in the form of heat. This means that the system is losing energy and its internal energy is decreasing.

How is q(system) related to the first law of thermodynamics?

The first law of thermodynamics states that energy cannot be created or destroyed, only transferred or converted. Q(system) is a measure of the energy transferred in or out of a system, making it directly related to the first law of thermodynamics.

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