Answer : The enthalpy change during the reaction is -6.48 kJ/mole
Explanation :
First we have to calculate the heat gained by the reaction.
![q=m\times c\times (T_{final}-T_{initial})](https://tex.z-dn.net/?f=q%3Dm%5Ctimes%20c%5Ctimes%20%28T_%7Bfinal%7D-T_%7Binitial%7D%29)
where,
q = heat gained = ?
m = mass of water = 100 g
c = specific heat = ![4.04J/g^oC](https://tex.z-dn.net/?f=4.04J%2Fg%5EoC)
= final temperature = ![26.6^oC](https://tex.z-dn.net/?f=26.6%5EoC)
= initial temperature = ![25.0^oC](https://tex.z-dn.net/?f=25.0%5EoC)
Now put all the given values in the above formula, we get:
![q=100g\times 4.04J/g^oC\times (26.6-25.0)^oC](https://tex.z-dn.net/?f=q%3D100g%5Ctimes%204.04J%2Fg%5EoC%5Ctimes%20%2826.6-25.0%29%5EoC)
![q=646.4J](https://tex.z-dn.net/?f=q%3D646.4J)
Now we have to calculate the enthalpy change during the reaction.
![\Delta H=-\frac{q}{n}](https://tex.z-dn.net/?f=%5CDelta%20H%3D-%5Cfrac%7Bq%7D%7Bn%7D)
where,
= enthalpy change = ?
q = heat gained = 23.4 kJ
n = number of moles barium chloride = ![\frac{\text{Mass of barium chloride}}{\text{Molar mass of barium chloride}}=\frac{20.8g}{208.23g/mol}=0.0998mole](https://tex.z-dn.net/?f=%5Cfrac%7B%5Ctext%7BMass%20of%20barium%20chloride%7D%7D%7B%5Ctext%7BMolar%20mass%20of%20barium%20chloride%7D%7D%3D%5Cfrac%7B20.8g%7D%7B208.23g%2Fmol%7D%3D0.0998mole)
![\Delta H=-\frac{646.4J}{0.0998mole}=-6476.95J/mole=-6.48kJ/mole](https://tex.z-dn.net/?f=%5CDelta%20H%3D-%5Cfrac%7B646.4J%7D%7B0.0998mole%7D%3D-6476.95J%2Fmole%3D-6.48kJ%2Fmole)
Therefore, the enthalpy change during the reaction is -6.48 kJ/mole
Exothermic:
An Exothermic reaction is a chemical reaction that expels energy in the form of heat/light. Everything a Endothermic does not do. Pretty simple for this one
reactants → products + energy.
For future reference - Exo means release, thermic means heat.
<u>Energy is a Reactant </u>
<u />
<u>_________________________________________________________</u>
Endothermic:
An Endothermic reaction essentially is draining the heat energy from anything its its surroundings. Usually its just heat but can also be salt dissolving it water or ice melting. Another example would be frost on your windshield evaporating.
It is the exact opposite of an Exothermic reaction.
<u>Energy is a Product</u>
Hydrogen atoms one outer electron so would be placed in group 1. However all group 1 elements are metals and elements in the same group have similar properties. Hydrogen is a non-metal and does not behave in the same way as the other group 1 elements, so that is why it is on its own.
Answer:
C21H30O5
Explanation:
Cortisol with molecular formula C21H30O5 is a steroid hormone released by adrenal glands, it is involved in protein synthesis and can also help to control blood sugar level .
Answer: The density of glycerine is ![78.589\frc{pounds}{foot^3}](https://tex.z-dn.net/?f=78.589%5Cfrc%7Bpounds%7D%7Bfoot%5E3%7D)
Explanation: We are given density of glycerine in
which is ![1.26g/cm^3](https://tex.z-dn.net/?f=1.26g%2Fcm%5E3)
To convert t into
, we are given conversion rates:
454 grams = 1 pound
So, 1 gram will be equal to ![\frac{1}{454}pounds](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B454%7Dpounds)
Similarly,
![28317cm^3=1foot^3](https://tex.z-dn.net/?f=28317cm%5E3%3D1foot%5E3)
So,
will be equal to ![\frac{1}{28317}foot^3](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B28317%7Dfoot%5E3)
Converting the density of glycerin from
to
using above conversion rates, we get:
![\frac{1.26g}{cm^3}=(\frac{1.26}{454}\times \frac{28317}{1})\frac{pounds}{foot^3}](https://tex.z-dn.net/?f=%5Cfrac%7B1.26g%7D%7Bcm%5E3%7D%3D%28%5Cfrac%7B1.26%7D%7B454%7D%5Ctimes%20%5Cfrac%7B28317%7D%7B1%7D%29%5Cfrac%7Bpounds%7D%7Bfoot%5E3%7D)
![1.26g/cm^3=78.589pounds/foot^3](https://tex.z-dn.net/?f=1.26g%2Fcm%5E3%3D78.589pounds%2Ffoot%5E3)
Density of glycerin is ![78.589\frc{pounds}{foot^3}](https://tex.z-dn.net/?f=78.589%5Cfrc%7Bpounds%7D%7Bfoot%5E3%7D)