Answer:
Because the optimal range of buffering for a formic acid potassium formate buffer is 2.74 ≤ pH ≤ 4.74.
Explanation:
Every buffer solution has an optimal effective range due to pH = pKa ± 1. Outside this range, there is not enough acid molecules or conjugate base molecules to sustain the pH without variation. There is a certain amount of both molecules that has to be in the solution to maintain a pH controlled.
Being for the formic acid the pKa 3.74, the optimal effective range is between 2.74 and 4.74. Upper or lower these range a formic acid/potassium formate buffer does not work.
Answer:
The relative humidity is 36%.
Explanation:
Relative humidity is the measure of ratio of actual vapor density to saturated vapor density in a given system. So there are different ways to measure the relative humidity in the atmosphere. One of the common ways is to measure using Psychrometer. In this instrument, two different thermometers are used as measuring device. One of the thermometer measures the humidity in dry air and another in wet air. So the difference of the temperature of dry and wet air bulb will be related to determine the relative humidity percentage. The formula to determine the relative humidity using this method is as below.
![Relative humidity=\frac{(e_{w}-[N*(1+0.00115*T_{w}*(T_{d}-T_{w}))])*100}{e_{d} }](https://tex.z-dn.net/?f=Relative%20humidity%3D%5Cfrac%7B%28e_%7Bw%7D-%5BN%2A%281%2B0.00115%2AT_%7Bw%7D%2A%28T_%7Bd%7D-T_%7Bw%7D%29%29%5D%29%2A100%7D%7Be_%7Bd%7D%20%7D)
Also,
![e_{d}=6.112*e^{[\frac{(17.502*T_{d} )}{(240.97+T_{d} )}]}](https://tex.z-dn.net/?f=e_%7Bd%7D%3D6.112%2Ae%5E%7B%5B%5Cfrac%7B%2817.502%2AT_%7Bd%7D%20%29%7D%7B%28240.97%2BT_%7Bd%7D%20%29%7D%5D%7D)
And,
![e_{w}=6.112*e^{[\frac{(17.502*T_{w} )}{(240.97+T_{w} )}]}](https://tex.z-dn.net/?f=e_%7Bw%7D%3D6.112%2Ae%5E%7B%5B%5Cfrac%7B%2817.502%2AT_%7Bw%7D%20%29%7D%7B%28240.97%2BT_%7Bw%7D%20%29%7D%5D%7D)
Here e =2.718,
and
are the temperature at dry bulb and wet bulb temperatures, respectively.
So, the relative humidity after substituting the values of Td = 2 C and Tw = -2 C is 36%.
Answer:
C. 3.0
Explanation:
Bond order is number of the bonding pairs of the electrons between two atoms.
For
,
The total number of the valence electrons = 2(4) + 1(5) + 3(1) = 16
The Lewis structure is drawn in such a way that the octet of each atom and duet for the hydrogen in the molecule is complete. So,
The Lewis structure is:
H
:
H : C : C : : : N :
:
H
Bond pairs between C and N is 3
<u>So bond pair is 3.</u>
A) true
b) false The atomic mass is never less than the atomic number.
c) this one is a bit tricky. For hydrogen, the atomic mass can equal the atomic number IF you are rounding the mass to the nearest whole number. That only works for hydrogen, though
d) false The larger the element, the more neutrons that are needed to keep the nucleus stable.
e) true
f) true