<span>From the above given choices :
melting is an endothermic process</span>
<u>Ans: Acetic acid = 90.3 mM and Sodium acetate = 160 mM</u>
Given:
Acetic Acid/Sodium Acetate buffer of pH = 5.0
Let HA = acetic acid
A- = sodium acetate
Total concentration [HA] + [A-] = 250 mM ------(1)
pKa(acetic acid) = 4.75
Based on Henderson-Hasselbalch equation
pH = pKa + log[A-]/[HA]
[A-]/[HA] = 10^(pH-pKa) = 10^(5-4.75) = 10^0.25 = 1.77
[A-] = 1.77[HA] -----(2)
From (1) and (2)
[HA] + 1.77[HA] = 250 mM
[HA] = 250/2.77 = 90.25 mM
[A-] = 1.77(90.25) = 159.74 mM
Answer: -
The acceleration due to gravity at height r = a = GM/r²
Rearranging
r² = GM /a
= (6.674 x 10⁻¹¹ x 5.972 x 10²⁴ ) / 5
r = 8.917 x 10⁶ m
r = 8917 Km
Now Radius of earth = 6371 Km
So height = 8917 - 6371 = 2546 Km
Carbohydrates! hope this helped!