Answer:
pH = 2.462.
Explanation:
Hello there!
In this case, according to the reaction between nitrous acid and potassium hydroxide:
It is possible to compute the moles of each reactant given their concentrations and volumes:
Thus, the resulting moles of nitrous acid after the reaction are:
So the resulting concentration considering the final volume (20.00mL+13.27mL) is:
![[HNO_2]=\frac{6.73x10^{-4}mol}{0.01327L+0.02000L} =0.02023M](https://tex.z-dn.net/?f=%5BHNO_2%5D%3D%5Cfrac%7B6.73x10%5E%7B-4%7Dmol%7D%7B0.01327L%2B0.02000L%7D%20%3D0.02023M)
In such a way, we can write the ionization of this weak acid to obtain:
So we can set up its equilibrium expression to obtain x as the concentration of H3O+:
![Ka=\frac{[NO_2^-][H_3O^+]}{[HNO_2]}\\\\7.1x10^{-4}=\frac{x^2}{0.02023M-x}](https://tex.z-dn.net/?f=Ka%3D%5Cfrac%7B%5BNO_2%5E-%5D%5BH_3O%5E%2B%5D%7D%7B%5BHNO_2%5D%7D%5C%5C%5C%5C7.1x10%5E%7B-4%7D%3D%5Cfrac%7Bx%5E2%7D%7B0.02023M-x%7D)
Next, by solving for the two roots of x, we get:
Whereas the correct value is 0.003451 M. Finally, we compute the resulting pH:
Best regards!
Answer:
Q = 306 kJ
Explanation:
Given that,
Mass, m = 60 kg
Specific heat, c = 1020 J/kg°C
The temperature changes from 20°C to 25°C.
Let Q be the change in thermal energy. The formula for the heat released is given by :
Put all the values,
So, 306 kJ is the change in thermal energy.
Answer:
. B. The boxes must minimize thermal energy transfer to prevent thermal energy from transferring into the boxes.
Explanation:
If a box is to remain cool, energy transfer into the box must be minimized and energy transfer out of the box must be maximized.
This implies that only a minimal amount of thermal energy can transfer into the box while the box looses heat rapidly. If a box is this designed, it is likely to remain cool.
Answer:
Cohesion
Explanation:
Think of it like this. The water molecules STICK TOGETHER, so they COoperate.
COhesion COoperate
Answer:
254.5 K
Explanation:
Data Given
initial volume V1 of neon gas = 12.5 L
final Volume V2 of neon gas = 10.5 L
initial Temperature T1 of neon gas = 30 °C
convert Temperature to Kelvin
T1 = °C +273
T1 = 30°C + 273 = 303 K
final Temperature T2 of neon gas = ?
Solution:
This problem will be solved by using Charles' law equation at constant pressure.
The formula used
V1 / T1 = V2 / T2
As we have to find out Temperature, so rearrange the above equation
T2 = V2 x T1 / V1
Put value from the data given
T2 = 10.5 L x 303 K / 12.5 L
T2 = 254.5K
So the final Temperature of neon gas = 254.5 K
