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!
For metals, reactivity increases down a group and from right to left across a period. Non metals, reactivitt increases up a grouo and from left to right across a period. Francium is the most reactive metal and fluorine is the most reactive non-metal.
V (speed) = f (frequency) * y (meant to be lambda) (wavelength)
y = v/f (v is speed of light --3.0*10^8m/s)
y = 3.0*10^8/1.5*10^13
The answer is y = 2.0*10-5.
Answer:
C₁₀H₁₂
Explanation:
90.8% of basketane (Hydrocarbon, contains only C and H) is Carbon, and 100-90.8 = 9.2% of the mass is hydrogen.
The molar mass is between 130-140g/mol, That means the moles of Carbon (Using its molar mass, 12.01g/mol) that are in basketane are between:
140g/mol /12.01g/mol *90.8%= 10.58 moles of C.
130g/mol / 12.01g/mol *90.8%= 9.83 moles of C.
As the moles of carbon must be given in a whole number, There are 10 moles of Carbon.
10 moles C * (12.01g / mol) = 120.1g/mol that are 90.8% of the molar mass. Molar mass of basketane is:
100% * (120.1g/mol / 90.8%) =
132.3g/mol.
The part of the molar mass due hydrogen must be:
132.3 g/mol - 120.1g/mol = 12.2 g/mol
As molar mass of hydrogen is 1g/mol, the moles of hydrogen are 12
And molecular formula is:
<h3>C₁₀H₁₂</h3>
