Answer:
pKa = 3.675
Explanation:
∴ <em>C</em> X-281 = 0.079 M
∴ pH = 2.40
let X-281 a weak acid ( HA ):
∴ HA ↔ H+ + A-
⇒ Ka = [H+] * [A-] / [HA]
mass balance:
⇒<em> C</em> HA = 0.079 M = [HA] + [A-]
⇒ [HA] = 0.079 - [A-]
charge balance:
⇒ [H+] = [A-] + [OH-]... [OH-] is negligible; it comes from to water
⇒ [H+] = [A-]
∴ pH = - log [H+] = 2.40
⇒ [H+] = 3.981 E-3 M
replacing in Ka:
⇒ Ka = [H+]² / ( 0.079 - [H+] )
⇒ Ka = ( 3.981 E-3 )² / ( 0.079 - 3.981 E-3 )
⇒ Ka = 2.113 E-4
⇒ pKa = - Log ( 2.113 E-4 )
⇒ pKa = 3.675
Ranking of the atom from highest to lowest is as follows:
Highest
Arrow = from outer edge to center
2nd Highest
Arrow = second closest ring to the outer edge to center
3rd Highest
Arrow = middle circle to center
Lowest
Arrow = outer edge to middle circle
Answer:
81 L gas
General Formulas and Concepts:
<u>Ideal Gas Law</u>
- STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 K
<u>Stoichiometry</u>
- Using Dimensional Analysis
Explanation:
<u>Step 1: Define</u>
[Given] 3.6 mols gas at STP
[Solve] volume (L) of gas
<u>Step 2: Convert</u>
- [DA] Set up:

- [DA] Multiply [Cancel out units]:

<u>Step 3: Check</u>
<em>Follow sig fig rules and round. We are given 2 sig figs.</em>
80.64 L gas ≈ 81 L gas
Answer: the moon passes through the earth's shadow
Explanation:
In this case the earth's shadow blocks the sun's light which normally is reflected off the moon's surface. So since the sunlight is blocked by the earth we call this a lunar eclipse
Recall that 1 gallon = 3.785 L, and 1 L = 1000 mL, so to calculate volume in millilitres, multiply by 3.785 and 1000, resulting in 3785 mL. Next, multiply volume by density to calculate mass (Density = Mass/Volume), so 3785 mL * 1.000 g / mL = 3785 g of water.