Answer:
pKa of the histidine = 9.67
Explanation:
The relation between standard Gibbs energy and equilibrium constant is shown below as:
![\Delta{G^0} =-RT \ln \frac{[His]}{[His+]}](https://tex.z-dn.net/?f=%5CDelta%7BG%5E0%7D%20%3D-RT%20%5Cln%20%5Cfrac%7B%5BHis%5D%7D%7B%5BHis%2B%5D%7D)
R is Gas constant having value = 0.008314 kJ / K mol
Given temperature, T = 293 K
Given, 
So, Applying in the equation as:-
![15\ kJ/mol=-0.008314\ kJ/Kmol\times 293\ K\times \ln \frac{[His]}{[His+]}](https://tex.z-dn.net/?f=15%5C%20kJ%2Fmol%3D-0.008314%5C%20kJ%2FKmol%5Ctimes%20293%5C%20K%5Ctimes%20%5Cln%20%5Cfrac%7B%5BHis%5D%7D%7B%5BHis%2B%5D%7D)
Thus,
![\frac{[His]}{[His+]}=e^{\frac{15}{-0.008314\times 293}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BHis%5D%7D%7B%5BHis%2B%5D%7D%3De%5E%7B%5Cfrac%7B15%7D%7B-0.008314%5Ctimes%20293%7D)
![\frac{[His]}{[His+]}=0.00211](https://tex.z-dn.net/?f=%5Cfrac%7B%5BHis%5D%7D%7B%5BHis%2B%5D%7D%3D0.00211)
Also, considering:-
![pH=pKa+log\frac{[His]}{[His+]}](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%5Cfrac%7B%5BHis%5D%7D%7B%5BHis%2B%5D%7D)
Given that:- pH = 7.0
So, 
<u>pKa of the histidine = 9.67</u>
Answer:
_2Mg + _O2 --≥2MgO this is balanced
Answer:
0.628 M.
Explanation:
In order to solve this problem we need to keep in mind the<em> definition of molarity</em>:
- Molarity = moles / liters
We are given both the <em>number of moles and the volume of solution</em>, meaning we can now proceed to <u>calculate the molarity</u>:
- Molarity = 0.220 mol / 0.350 L
Sound waves are most effective when traveling through solids. Less effective when in liquids and least effective in air.
Water has a density of 1 g/cc. If you have 1 cc of water, then the mass it contains would be 1 g. <span>Density is a physical
property of a substance that represents the mass of that substance per unit
volume. It is a property that can be used to describe a substance. Hope this answers the question. Have a nice day.</span>
