Answer: The correct answer is: " endothermic . "
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<u>Note</u>: Heat flows <u> into </u> [heat <u> may be </u> absorbed within] an "<u>endothermic</u>" reaction or system
To the contrary, heat flows <u> </u><u>out </u> [heat <u> may </u><em> </em>exit from or <u> may be </u> released from] an "<u>exothermic</u>" reaction or process.
<u>Hint</u>: Think of the "prefixes" of: "<u>endo</u>thermic" and "<u>exo</u>thermic" :
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1) endo- = "within" (as in "endothermic" —heat tends to be absorbed/"within"/"released within"/released within"/into" ;
2) exo- = " outwards"/"exit" (as in "exothermic") —heat tends to '"exit"/leave/escape from/"be released out of/form".
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Hope this is helpful to you!
Best wishes to you in your academic pursuits
—and within the "Brainly" community"!
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Explanation:
No of molecules=0.500×6.023×10²³=3.011×10²³ molecules
Muscle is the newer hope it helps
Answer:

Explanation:
Hello there!
In this case, since the modelling of titration problems can be approached via the Henderson-Hasselbach equation to set up a relationship between pH, pKa and the concentration of the acid and its conjugate base, we can write:
![pH=pKa+log(\frac{[NO_2^-]}{[HNO_2]} )](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%5Cfrac%7B%5BNO_2%5E-%5D%7D%7B%5BHNO_2%5D%7D%20%29)
Whereas the pH is given as 3.14 and the concentrations are the same, that is why the pH would be equal to the pKa as the logarithm gets 0 (log(1)=0); thus, we can calculate the Ka via:

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