Answer:
I dont undarsatnd 2gebwhsanKM<dwkdwndwkjdwnfwkjdnfkwnfwkf
Explanation:
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beryllium, magnesium, strontium,barium<span>, and </span><span>radium. </span>
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:
Molar absorptivity or molar extinction co-effecient = 2120.14 cm⁻¹M⁻¹
Explanation:
First convert Concentration from ppm inM or mol/l
⇒ Molar mass of KMnO₄ = 158.03 g
⇒ 4.48 ppm = 4.48 mg/l = 4.48 x 10⁻³ g/l
⇒ Molarity = 
= 2.83 x 10⁻⁵ molar
Absorbance (A) = - log(T) ( T = % transmittance)
= - log(0.859)
= 0.06
According to Lambert Beer's law
ε = 
or, ε = 
or, ε = 2120.14 cm⁻¹M⁻¹
Where
ε = Molar absorptivity
A = absorbance
C = Molar concentration of KMnO₄ solution
l = length
