Answer:
a. Phosphoric Acid
b. Acetic Acid
c. Hypochlorous Acid
Explanation:
A buffer works when the pH of this one is in pKa ± 1. That means, to find which buffer system works in some pH you need to find pKa:
pKa = -log Ka
<em>pKa Acetic acid:</em>
-log1.8x10⁻⁵ = 4.74
<em>pKa phosphoric acid:</em>
-log7.5x10⁻³ = 2.12
<em>pKa hypochlorous acid:</em>
-log3.5x10⁻⁸ = 7.46
a. For a pH of 2.8 the best choice is phophoric acid because its effective range is: 1.12 - 3.12 and 2.8 is between these values.
b. pH 4.5. Acetic acid. effective between pH's 3.74 - 5.74
c. pH 7.5. Hypochlorous acid that works between 6.46 and 8.46
Answer:
the correct option is B
Explanation:
The correct option is b, since if we reach pH 7, it means that the acid-base reaction is neutralized, therefore the base has been neutralized by an acid or vice versa, without taking into account the proteins or the amounts of both components .
Answer:
X 86 206
Explanation:
Radioactive atoms are nuclei that can under go disintegration to emit either an alpha particle, beta particle or gamma radiation. The process could be spontaneous or stimulated.
When a radioactive atom R 88 210 emits alpha particle, it would produce an element with atomic number 86 and mass number 206 i.e X 86 206. An alpha particle is usually a helium nucleus.
⇒
+
+ energy
<u>Answer:</u> The pressure that must be applied to the apparatus is 0.239 atm
<u>Explanation:</u>
To calculate the osmotic pressure, we use the equation for osmotic pressure, which is:

or,

where,
= osmotic pressure of the solution
i = Van't hoff factor = 1 (for non-electrolytes)
= mass of sucrose = 3.40 g
= molar mass of sucrose = 342.3 g/mol
= Volume of solution = 1 L
R = Gas constant = 
T = temperature of the solution = ![20^oC=[20+273]K=293K](https://tex.z-dn.net/?f=20%5EoC%3D%5B20%2B273%5DK%3D293K)
Putting values in above equation, we get:

Hence, the pressure that must be applied to the apparatus is 0.239 atm
The molar mass of monotonic Nitrogen is 14 g/mol. Since this is diatomic Nitrogen, double that to 28 g/mol.
Next, divide total mass by molar mass, 500 g / 28 g/mol, which gives <span>17.8571 moles. A mole is defined as being 6.022*10^23 molecules, so multiply moles by molecules/mol (Avogadro's number), and we finally end up with something like 1.075 * 10^25, give or take a few billion particles.</span>