A piston compresses the air in the cylinder by doing 61.0 J of work on the air. As a result, the air gives off 113.0 J of heat to the surroundings. If the system is the air in the cylinder, what is the change in its internal energy?

Explanation:

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In this case, since the first law of thermodynamics states that the heat added to system and the work done by the system are able to define the change in the internal energy as follows:

Since this problem shows that the system releases 113.0 J of heat, we use it negative as well as the 61.0 J of work performed on the system; therefore we write:

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answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.