Answer:
56.9 mmoles of acetate are required in this buffer
Explanation:
To solve this, we can think in the Henderson Hasselbach equation:
pH = pKa + log ([CH₃COO⁻] / [CH₃COOH])
To make the buffer we know:
CH₃COOH + H₂O ⇄ CH₃COO⁻ + H₃O⁺ Ka
We know that Ka from acetic acid is: 1.8×10⁻⁵
pKa = - log Ka
pKa = 4.74
We replace data:
5.5 = 4.74 + log ([acetate] / 10 mmol)
5.5 - 4.74 = log ([acetate] / 10 mmol)
0.755 = log ([acetate] / 10 mmol)
10⁰'⁷⁵⁵ = ([acetate] / 10 mmol)
5.69 = ([acetate] / 10 mmol)
5.69 . 10 = [acetate] → 56.9 mmoles
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:
Oxygen and magnesium come together in a chemical reaction to form this compound. After it burns, it forms a white powder of the magnesium oxide. Magnesium gives up two electrons to oxygen atoms to form this powdery product. This is an exothermic reaction.
If pH is less than seven (pH<7), solution is acidic.
If pH is equal seven (pH = 7), solution is neutral.
If pH is greater than seven (pH > 7), solution is basic.
Some examples:
1) Acidic - gastric juices pH 1, lemon juice pH 2.2, tomato juice pH 4.
2) Neutral - salt solution pH 7.
3) Alkaline - baking soda pH 9, bleach pH 13.
pH is a numeric scale used to specify the acidity or basicity of an aqueous solution.
For, ClO3- there are 26 valence electrons, so total pairs of electrons are 13.
