Answer:
See Explanation
Explanation:
An endothermic reaction is one in which energy is absorbed and the change in enthalpy for the reaction is positive.
If we look at the reaction 2HgO + 45kcal ----> 2Hg + O2; we will notice that
i) 45kcal of energy was taken in (absorbed) for the reaction to occur
ii) The value of the reaction enthalpy is positive
For these two reasons, the reaction is an endothermic reaction as written.
Answer:
Streak is tested by scraping a mineral across plate
Explanation: Hope this helps :)
Blue
When red litmus paper comes into contact with any alkaline substance, it turns blue. Some examples of alkaline substances are ammonia gas, milk of magnesia, baking soda and limewater.
Aqua regia is an oxidative mixture that is highly corrosive and is composed of hydrochloric acid and nitric acid. The Ea (rev) for the reaction is 3 kJ.
<h3>What is activation energy?</h3>
The activation energy is the minimum required energy by the reactant to undergo changes to form the product. The activation energy of the reverse reaction is given by the difference in the production state and transition state.
It is given as,
Ea (rev) = Ea (fwd) − ΔHrxn
Given,
ΔH° = 83KJ
Ea (fwd) = 86 kJ/mol
Substituting the values above as:
Ea (rev) = 86 - 83
= 3 kJ
Therefore, the activation energy of the reverse reaction is 3 kJ.
Learn more about activation energy, here:
brainly.com/question/14287952
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