<span>The most efficient way to determine whether a reaction is an exothermic chemical reaction is to use a temperature probe.
Given that an exothermic chemical reaction is going to release heat, using an instrument such as a thermometer or a temperature probe to see the change in temperature would be the best way in order to determine the type of the chemical reaction.
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organic chemistry, the hydroboration–oxidation reaction is a two-step organic reaction that converts an alkene into a neutral alcohol by the net addition of water across the double bond. The hydrogen and hydroxyl group are added in a syn addition leading to cis stereochemistry. Hydroboration–oxidation is an anti-Markovnikov reaction, with the hydroxyl group attaching to the less-substituted carbon.
H2O- H+ O2-. YES HYDROGEN ARE MADE UP OF HYDROGEN AND OXYGEN ATOMS
The answer is (4) solid to gas. The entropy is the measurement of disorder. The entropy of CO2 under different status will increase from solid to liquid to gas. So the answer is (4).