Answer:
1.75L
Explanation:
Reaction of decomposition is:
2KClO₃(s) → 2KCl(s) + 3O₂(g)
We determine moles of salt:
4.35 g . 1 mol /122.55 g = 0.0355 moles
Ratio is 2:3. 2 moles of salt can produce 3 moles of oxygen
Then, our 0.0355 moles of chlorate may produce (0.0355 . 3)/ 2 = 0.0532 moles.
We have determined, moles of gas and we have data of pressure and temperature. To find out the volume, we apply the Ideal Gases Law:
We convert T° from °C to K → 27°C + 273 = 300K
P . V = n . R . T
0.75 atm . V = 0.0532 mol . 0.0821 L.atm/mol.K . 300K
V = (0.0532 mol . 0.0821 L.atm/mol.K . 300K) / 0.75 atm
V = 1.75 Liters
B, a physical change because it is not destroying the substance.
Answer:
[HAc] = 0.05M
[Ac⁻] = 0.20M
Explanation:
The Henderson-Hasselbalch formula for the acetic acid buffer is:
pH = pka + log₁₀ [Ac⁻] / [HAc]
Replacing:
5.36 = 4.76 + log₁₀ [Ac⁻] / [HAc]
3.981 = [Ac⁻] / [HAc] <em>(1)</em>
Also, as total concentration of buffer is 0.25M it is possible to write:
0.25M = [Ac⁻] + [HAc] <em>(2)</em>
Replacing (2) in (1)
3.981 = 0.25M - [HAc] / [HAc]
3.981 [HAc] = 0.25M - [HAc]
4.981 [HAc] = 0.25M
<em>[HAc] = 0.05M</em>
Replacing this value in (2):
0.25M = [Ac⁻] + 0.05M
<em>[Ac⁻] = 0.20M</em>
I hope it helps!
Answer:
0.0055 seconds
Explanation:
To answer this question you need to know the equivalence:
1 second (s) = 5.5 (miliseconds) (ms)
Then you use the conversion factor:
-Put the value given and the units:

- Put in the denominator the equivalence with the same units:

- Put in the numerator the unit at which you want to convert the value given:

- Then multiply and divide the quantities:

Note that the same units in numerator and denominator are cancelled.
Answer:
pH = 5.76
Explanation:
We can solve this problem by using<em> Henderson-Hasselbach's equation</em>:
pH = pKa + log![\frac{[SodiumAcetate]}{[AceticAcid]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BSodiumAcetate%5D%7D%7B%5BAceticAcid%5D%7D)
We are already know all the required information, thus we<u> input the data given by the problem</u>:
pH = 4.76 + log(20/2)
And finally <u>calculate the pH</u>:
pH = 5.76
The pH of that acetic acid solution is 5.76.