A new potential heart medicine, code-named X-281, is being tested by a pharmaceutical company, Pharma-pill. As a research techni
1 answer:
Answer:
a. pka = 3,73.
b. pkb = 10,27.
Explanation:
a. Supposing the chemical formula of X-281 is HX, the dissociation in water is:
HX + H₂O ⇄ H₃O⁺ + X⁻
Where ka is defined as:
In equilibrium, molar concentrations are:
[HX] = 0,089M - x
[H₃O⁺] = x
[X⁻] = x
pH is defined as -log[H₃O⁺]], thus, [H₃O⁺] is:
[H₃O⁺] = <em>0,004M</em>
Thus:
[X⁻] = 0,004M
And:
[HX] = 0,089M - 0,004M = <em>0,085M</em>
ka = 1,88x10⁻⁴
And <em>pka = 3,73</em>
b. As pka + pkb = 14,00
pkb = 14,00 - 3,73
<em>pkb = 10,27</em>
I hope it helps!
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Molar mass of = 39.1 + 35.5 + 3(16.0) = 122.6 g
Molar mass of KCl = 39.1 + 35.5 = 74.6 g
Molar mass of = 32.0 g
According to the equation, 2 moles of reacts to give 3 moles of oxygen.
Therefore, 2 (122.6) = 245.2 g of will give 3 (32.0) = 96.0 g of oxygen. Thus, 245.2 g of
gives 96.0 g of oxygen.
(a) Calculate the amount of oxygen given by 2.72 g of as follows.
of
(b) Calculate the amount of oxygen given by 0.361 g of as follows.
of
c) Calculate the amount of oxygen given by 83.6 kg as follows.
of
Convert kg into grams as follows.
= 32731 g of
(d) Calculate the amount of oxygen given by 22.5 mg of as follows.
Convert mg into grams as follows.
of
Answer:
0.444 mol/L
Explanation:
First step is to find the number of moles of oxalic acid.
n(oxalic acid) =
Now use the molar ratio to find how many moles of NaOH would be required to neutralize of oxalic acid.
n(oxalic acid): n(potassium hydroxide)
1 : 2 (we get this from the balanced equation)
: x
x = 0.0111 mol
Now to calculate what concentration of KOH that would be in 25 mL of water: