Answer:
Option B
Explanation:
As Brønsted-Lowry theory states, acids are the ones that can donate protons.
When a proton is donated, it is released to become medium more acidic.
HCl is a strong acid.
HCl (l) + H₂O (l) → H₃O⁺ (aq) + Cl⁻(aq)
These always reffers to strong acid where the dissociation is 100% completed.
In a weak acid, dissociation is not 100% complete, that's why we have an equilibrium.
HA (l) + H₂O (l) ⇄ H₃O⁺ (aq) + A⁻(aq) Ka
We are given
0.2 M HCHO2 which is formic acid, a weak acid
and
0.15 M NaCHO2 which is a salt which can be formed by reacting HCHO2 and NaOH
The mixture of the two results to a basic buffer solution
To get the pH of a base buffer, we use the formula
pH = 14 - pOH = 14 - (pKa - log [salt]/[base])
We need the pKa of HCO2
From, literature, pKa = 1.77 x 10^-4
Substituting into the equation
pH = 14 - (1.77 x 10^-4 - log 0.15/0.2)
pH = 13.87
So, the pH of the buffer solution is 13.87
A pH of greater than 7 indicates that the solution is basic and a pH close to 14 indicates high alkalinity. This is due to the buffering effect of the salt on the base.
Answer:
See detailed explanation.
Explanation:
Hello!
i. In this case, since the given chemical reaction is exothermic due to the negative change in the enthalpy of reaction, we infer that according to the mentioned principle, by lowering the temperature the reaction will shift rightwards and therefore the yield is increased; thus, you need a lower temperature than the specified.
ii. In this case, since the reaction has less moles at the products side, according to the mentioned principle it'd be necessary to rise the pressure in order to increase the yield, since the increase of pressure favors the reaction side with the fewest number of moles.
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