Calculate the root mean square velocity of nitrogen molecules at 25°C.
297 m/s
149 m/s
515 m/s
729 m/s
Answer:
186.9Kelvin
Explanation:
The ideal gas law equation is PV
=
n
R
T
where
P is the pressure of the gas
V is the volume it occupies
n is the number of moles of gas present in the sample
R is the universal gas constant, equal to 0.0821
atm L
/mol K
T is the absolute temperature of the gas
Ensure units of the volume, pressure, and temperature of the gas correspond to R
( the universal gas constant, equal to 0.0821
atm L
/mol K
)
n
=
3.54moles
P= 1.57
V= 34.6
T=?
PV
=
n
R
T
PV/nR = T
1.57 x 34.6/3.54 x 0.0821
54.322/0.290634= 186.908620464= T
186.9Kelvin ( approximately to 1 decimal place)
Answer: Friction is a force that resists relative motion between two surfaces in contact. Depending on the application, friction may be desirable or undesirable.
Answer:
Buffer B has the highest buffer capacity.
Buffer C has the lowest buffer capacity.
Explanation:
An effective weak acid-conjugate base buffer should have pH equal to
of the weak acid. For buffers with the same pH, higher the concentrations of the components in a buffer, higher will the buffer capacity.
Acetic acid is a weak acid and
is the conjugate base So, all the given buffers are weak acid-conjugate base buffers. The pH of these buffers are expressed as (Henderson-Hasselbalch):
![pH=pK_{a}(CH_{3}COOH)+log\frac{[CH_{3}COO^{-}]}{[CH_{3}COOH]}](https://tex.z-dn.net/?f=pH%3DpK_%7Ba%7D%28CH_%7B3%7DCOOH%29%2Blog%5Cfrac%7B%5BCH_%7B3%7DCOO%5E%7B-%7D%5D%7D%7B%5BCH_%7B3%7DCOOH%5D%7D)

Buffer A: 
Buffer B: 
Buffer C: 
So, both buffer A and buffer B has same pH value which is also equal to
. Buffer B has higher concentrations of the components as compared to buffer A, Hence, buffer B has the highest buffer capacity.
The pH of buffer C is far away from
. Therefore, buffer C has the lowest buffer capacity.
Thermodynamic quantity equivalent to the total heat content of a system It is equal to the internal energy of the system plus the product of pressure and volume