Answer:
shorter wavelength = alpha wave
Explanation:
Given that,
The alpha wave has a frequency of 5 Hz and the beta wave has a frequency of 2 Hz.
We need to compare the wavelengths of these two waves.
For alpha wave,
For beta wave,
From the above calculations, we find that the wavelength of the alpha wave is shorter than the wavelength of the beta wave.
Answer:
You will need 9,0 g of acetic acid
Explanation:
The equilibrium acetate-acetic acid is:
CH₃COOH ⇄ CH₃COO⁻ + H⁺ pka = 4,76
Using Henderson-Hasselbalch you will obtain:
pH = pka + log₁₀
Where HA is acetic acid and A⁻ is acetate ion
4,90 = 4,76 + log₁₀
1,38 = <em>(1)</em>
As acetate concentration is 0,300M:
0,300M = [HA] + [A⁻] <em>(2)</em>
Replacing (2) in (1):
[HA] = 0,126 M
And:
[A⁻] = 0,174 M
As you need to produce 500 mL:
0,5 L × 0,126 M = 0,063 moles of acetic acid
0,5 L × 0,174 M = 0,087 moles of acetate
To produce moles of acetate from acetic acid:
CH₃COOH + NaOH → CH₃COO⁻ + Na⁺ + H₂O
Thus, moles of acetate are equivalents to moles of NaOH and all acetates comes from acetic acid, thus:
0,087 moles of acetate + 0,063 moles of acetic acid ≡ 0,15 moles of acetic acid × = <em>9,0 g of acetic acid</em>
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I hope it helps!