Answer:
Matter
Compound
Explanation:
Caffeine is NOT an Element, because it is formed by different elements (C, H, N, and O).
Caffeine is NOT an Isotope, because this only applies to elements with the same atomic number but different mass number.
Caffeine is Matter because it has mass and occupies space by having volume.
Caffeine is a Compound because it has a formula with a <em>definite constant composition</em> of different elements.
Sodium is a silver-colored metal which is soft enough to cut with a knife. It is an extremely reactive metal, and is always found naturally in ionic compounds, not in its pure metallic form. Pure sodium metal reacts violently (and sometimes explosively) with water, producing sodium hydroxide, hydrogen gas, and heat:
Chlorine is a poisonous, yellow-green gas, with a very sharp odor, a
Chemical change happen cuz these 2 elements will combine to form a new compound which’s NaCl ( table salt )
<em>Answer:</em>
<em>Ether:</em>
Ether are organic compounds that contain ether functional group , in which oxygen atom is connected with two alkyl or aryl group.
They have general formula as follow
- R---O---R or R'---O----R or R'---O---R'
while R = Alkyl
R' = Aryl
The pH of the buffer is 6.1236.
Explanation:
The strength of any acid solution can be obtained by determining their pH. Even the buffer solution strength of the weak acid can be determined using pH. As the dissociation constant is given, we can determine the pKa value as the negative log of dissociation constant value.
![pKa=-log[H] = - log [ 5.66 * 10^{-7}]\\ \\pka = 7 - log (5.66)=7-0.753=6.247\\\\pka = 6.247](https://tex.z-dn.net/?f=pKa%3D-log%5BH%5D%20%3D%20-%20log%20%5B%205.66%20%2A%2010%5E%7B-7%7D%5D%5C%5C%20%5C%5Cpka%20%3D%207%20-%20log%20%285.66%29%3D7-0.753%3D6.247%5C%5C%5C%5Cpka%20%3D%206.247)
The pH of the buffer can be known as
![pH = pK_{a} + log[\frac{[A-]}{[HA]}}]](https://tex.z-dn.net/?f=pH%20%3D%20pK_%7Ba%7D%20%2B%20log%5B%5Cfrac%7B%5BA-%5D%7D%7B%5BHA%5D%7D%7D%5D)
The concentration of ![[A^{-}] = Moles of [A]/Total volume = 0.608/2 = 0.304 M\\](https://tex.z-dn.net/?f=%5BA%5E%7B-%7D%5D%20%3D%20Moles%20of%20%5BA%5D%2FTotal%20volume%20%3D%200.608%2F2%20%3D%200.304%20M%5C%5C)
Similarly, the concentration of [HA] = 
Then the pH of the buffer will be
pH = 6.247 + log [ 0.304/0.404]

So, the pH of the buffer is 6.1236.