One liter contains __

If a 95.27 mL sample of acetic acid (HC2H3O2) is titrated to the equivalence point with 79.06 mL of 0.113 M KOH, what is the pH

KATRIN_1 [288]

Answer:

8.73

Explanation:

The concentration of acetic acid can be determined as follows:

$M_1V_1 = M_2V_2\\(KOH) = (CH_3COOH)$

$M_{KOH}=0.113 M\\V_{KOH}=79.06 mL$

$V_{CH_3COOH}=95.27 \\\\M_{CH_3COOH)=?????$

$M_{CH3COOH} = \frac{M_{KOH}*V_{KOH}}{V_{CH_3COOH}}$

$M_{CH3COOH} = \frac{0.113*79.06}{95.27}$

$M_{CH3COOH} = 0.094 M$

Moles of $CH_3COOH$ = $95.27* 10^{-3}* 0.094$

=0.0090 moles

Moles of $KOH = 79.06*10^{-3}*0.113$

= 0.0090 moles

The equation for the reaction can be expressed as :

$CH_3COOH$ $+$ $KOH$ -----> $CH_3COO^{-}K^+$ $+$ $H_2O$

Concentration of $CH_3COO^{-$ ion = $\frac{0.0090}{Total volume (L)}$

= $\frac{0.0090}{(95.27+79.06)} *1000$

= 0.052 M

Hydrolysis of $CH_3COO^{-$ ion:

$CH_3COO^{-$ $+$ $H_2O$ -----> $CH_3COOH$ $+$ $OH^-$

$K = \frac{K_w}{K_a} = \frac{x*x}{0.052-x}$

⇒ $\frac{10^{-14}}{1.82*10^{-5}}= \frac{x*x}{0.052-x}$

= $0.5494*10^{-9}= \frac{x*x}{0.052-x}$

As K is so less, then x appears to be a very infinitesimal small number

0.052-x ≅ x

$0.5494*10^{-9}= \frac{x^2}{0.052}$

$x^2 = 0.5494*10^{-9}*0.052$

$x^2 = 0.286*10^{-10$

$x = \sqrt{0.286*10^{-10$

$x =0.535*10^{-5}M$

$[OH] = x =0.535*10^{-5}$

$pOH = -log[OH^-]$

$pOH = -log[0.535*10^{-5}]$

$pOH = 5.27$

pH = 14 - pOH

pH = 14 - 5.27

pH = 8.73

Hence, the pH of the titration mixture = 8.73

8 0

3 years ago

C₂H₅0H+30₂→2CO₂+3H₂0,the change of enthalpy was ΔH= - 1235.7 KJ/mol

igor_vitrenko [27]

Answer:

The total enthalpy of the reaction has negative value which mean that the heat is lost during the chemical reaction into surroundings.

Explanation:

Exothermic reactions are defined as the reactions in which energy of reactants is more than the energy of the products. In these reactions, energy is released by the system.

The total enthalpy of the reaction $(\Delta H)$ comes out to be negative.

Endothermic reactions are defined as the reactions in which energy of products is more than the energy of the reactants. In these reactions, energy is absorbed by the system.

The total enthalpy of the reaction $(\Delta H)$ comes out to be positive.

$C_2H_5OH+3O_2\rightarrow 2CO_2+3H_2O$ ,ΔH= -1235.7 kJ/mol

The total enthalpy of the reaction has negative value which mean that the heat is lost during the chemical reaction into surroundings.

5 0

3 years ago

What is the enthalpy of combustion (per mole) of C3 H8 (g)?

Anarel [89]

The enthalpy of combustion of propane is -2202.0 kJ/mol.
The enthalpy of combustion is released when one mole of compound is burned in the presence of excess oxygen. The bonds between carbon and hydrogen in the compound are broken and bonds between carbon and oxygen are formed as well as bonds between hydrogen and oxygen are formed.

8 0

4 years ago

Read 2 more answers

You have 500.0 ml of a buffer solution containing 0.30 m acetic acid (ch3cooh) and 0.20 m sodium acetate (ch3coona). what will t

Nataly [62]

First, we should get moles acetic acid = molarity * volume

=0.3 M * 0.5 L

= 0.15 mol

then, we should get moles acetate = molarity * volume

= 0.2 M * 0.5L

= 0.1 mol

then, we have to get moles of OH- which added:

moles OH- = molarity * volume

= 1 M * 0.02L

= 0.02 mol

when the reaction equation is:

CH3COOH + OH- → CH3COO- + H2O

moles acetic acid after adding OH- = (0.15-0.02)

= 0.13M

moles acetate after adding OH- = (0.1 + 0.02)

= 0.12 M

Total volume = 0.5 L + 0.02 L= 0.52 L

∴[acetic acid] = moles acetic acid after adding OH- / total volume

= 0.13mol / 0.52L

= 0.25 M

and [acetate ) = 0.12 mol / 0.52L

= 0.23 M

by using H-H equation we can get PH:

PH = Pka + ㏒[salt/acid]

when we have Ka = 1.8 x 10^-5

∴Pka = -㏒Ka

= -㏒ 1.8 x 10^-5

= 4.7

So by substitution:

∴ PH = 4.7 + ㏒[acetate/acetic acid]

= 4.7 + ㏒(0.23/0.25)

= 4.66

6 0

3 years ago

An experiment was set up to test the hypothesis that all plants will grow faster in a "super soil" versus regular potting soil.

dolphi86 [110]

Answer:

add more types of plants

Explanation:are you kidding me i’m doing this stuff and i’m in 7th grade

5 0

4 years ago

One liter contains ___ mL.