Hello!
After the addition of a small amount of acid, a reasonable value of buffer pH would be
5,15.
If initially there are equal amounts of a weak acid and its conjugate base, the pH would be equal to the pKa, according to the
Henderson-Hasselbach equation:
![pH=pKa+log( \frac{[A^{-}] }{[HA]} ) \\ \\ if [A^{-}]=[HA] \\ \\ pH=pKa + log (1) \\ \\ pH=pKa + 0=5,25](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%20%5Cfrac%7B%5BA%5E%7B-%7D%5D%20%7D%7B%5BHA%5D%7D%20%29%20%5C%5C%20%5C%5C%20if%20%5BA%5E%7B-%7D%5D%3D%5BHA%5D%20%5C%5C%20%5C%5C%20pH%3DpKa%20%2B%20log%20%281%29%20%5C%5C%20%5C%5C%20pH%3DpKa%20%2B%200%3D5%2C25)
So, when adding a little amount of acid the pH should be only a little lower than the pKa. The value from the list that is a little lower than the pKa is
5.15
Have a nice day!
Answer:
1) -COOH
2) -NH2
3) hydrogen bonds
4) dispersion forces
5) -CH3
6) hydrogen bonds
7) negative
8) negative
9) positive
Explanation:
Alanine has a <u>-COOH</u> and a <u>-NH2</u> group available to form <u>hydrogen bonds</u> with water molecules.
Although there are some potential <u>dispersion forces</u> between the terminal <u>-CH3</u> group of alanine and hexane molecules, we expect the <u>hydrogen bonds</u> between alanine and water to be stronger.
Stronger intermolecular attractive forces between alanine and water lead to a more <u>negative ΔHmix</u> and more <u>negative (smaller positive)</u> ΔHsoln for water than for hexane.
Answer:
(a) Moles of ammonium chloride = 0.243 moles
(b) 
(c) 60.68 mL
Explanation:
(a) Mass of ammonium chloride = 13.0 g
Molar mass of ammonium chloride = 53.491 g/mol
The formula for the calculation of moles is shown below:
Thus,
<u>Moles of ammonium chloride = 0.243 moles</u>
(b) Moles of ammonium chloride = 0.243 moles
Volume = 295 mL = 0.295 L ( 1 mL = 0.001 L)
(c) Moles of ammonium chloride = 0.0500 moles
Volume = ?
Molarity = 0.824 M
<u>Volume = 0.05 / 0.824 L = 0.06068 L = 60.68 mL</u>
Answer:
Transfer of heat between two objects that are touching.
Explanation:
Conduction is the process by which heat is transferred from one object to another object that is touching and has different temperatures.
Eg: We can use a hot water pack to warm our back. Or While cooking we can feel the conduction process when heat process from the bottom of the pan to the top of the pan
Answer:
C: liquid
Explanation:
Liquid has the set volume as it cannot be compressed or 'expanded' like a gas. However, liquids will take the shape of the container you put them in so their shape can change.
