<span>*Acids taste sour. The lemon, vinegar, tamarind contain acids; that's why they are sour.
*The acids change the color of certain substances called indicators. The indicators have the property of changing color as the character acid or basic solutions. The litmus and phenolphthalein are indicators of acids and bases. The solution of phenolphthalein is colorless red in the presence of an acid. Already the blue litmus paper turns red.
*The acids react with bases to form salts and water. This reaction is called neutralization reaction.</span>
hope this helps!
36.46 g/mol is the answer
Answer:
The pH of the buffer is 7.0 and this pH is not useful to pH 7.0
Explanation:
The pH of a buffer is obtained by using H-H equation:
pH = pKa + log [A⁻] / [HA]
<em>Where pH is the pH of the buffer</em>
<em>The pKa of acetic acid is 4.74.</em>
<em>[A⁻] could be taken as moles of sodium acetate (14.59g * (1mol / 82g) = 0.1779 moles</em>
<em>[HA] are the moles of acetic acid (0.060g * (1mol / 60g) = 0.001moles</em>
<em />
Replacing:
pH = 4.74 + log [0.1779mol] / [0.001mol]
<em>pH = 6.99 ≈ 7.0</em>
<em />
The pH of the buffer is 7.0
But the buffer is not useful to pH = 7.0 because a buffer works between pKa±1 (For acetic acid: 3.74 - 5.74). As pH 7.0 is out of this interval,
this pH is not useful to pH 7.0
<em />
To get the ratio of the concentration of sodium acetate to the concentration of acetic acid we are going to use H-H equation:
when:
PH = Pka + ㏒[salt/acid]
when the Ka of acetic acid = 1.75 x 10^-5
so, we can get Pka from this formula:
Pka = -㏒Ka
= -㏒1.75 x 10^-5
= 4.76
and when we have PH = 5.75, so by substitution:
∴ 5.75 = 4.76 + ㏒[acetate/ acetic acid]
∴ [acetate/acetic acid] = 9.77
∴ the ratio of a concentration of acetate to acetic acid 9.77
