An s sublevel can hold how many electrons

In the laboratory, a general chemistry student measured the pH of a 0.529 M aqueous solution of phenol (a weak acid), C6H5OH to

Artyom0805 [142]

Answer:

The dissociation constant of phenol from given information is $9.34\times 10^{-11}$ .

Explanation:

The measured pH of the solution = 5.153

$C_6H_5OH\rightarrow C_6H_5O^-+H^+$

Initially c

At eq'm c-x x x

The expression of dissociation constant is given as:

$K_a=\frac{[C_6H_5O^-][H^+]}{[C_6H_5OOH]}$

Concentration of phenoxide ions and hydrogen ions are equal to x.

$pH=-\log[x]$

$5.153=-\log[x]$

$x=7.03\times 10^{-6} M$

$K_a=\frac{x\times x}{(c-x)}=\frac{x^2}{(c-x)}=\frac{(7.03\times 10^{-6} M)^2}{ 0.529 M-7.03\times 10^{-6} M}$

$K_a=9.34\times 10^{-11}$

The dissociation constant of phenol from given information is $9.34\times 10^{-11}$ .

4 0

4 years ago

Sort these species into isoelectronic groups. It doesn\'t matter which group goes in which box, so long as the correct species a

OleMash [197]

Answer : The isoelectronic groups are:

$He,Be^{2+},Li^{+}$

$N^{3-},Mg^{2+}$

$S^{2-},Ti^{4+},K^{+}$

Explanation :

Isoelectronic : It is defined as the compound or molecule having the same number of electrons and the same number of electronic structure.

The element is helium. The number of electrons are 2.
The element is beryllium. The number of electrons are 4. The number of electrons in $Be^{2+}$ = 4 - 2 = 2
The element is lithium. The number of electrons are 3. The number of electrons in $Li^{+}$ = 3 - 1 = 2
The element is nitrogen. The number of electrons are 7. The number of electrons in $N^{3-}$ = 7 + 3 = 10
The element is neon. The number of electrons are 10.
The element is sulfur. The number of electrons are 16. The number of electrons in $S^{2-}$ = 16 + 2 = 18
The element is magnesium. The number of electrons are 12. The number of electrons in $Mg^{2+}$ = 12 - 2 = 10
The element is titanium. The number of electrons are 22. The number of electrons in $Ti^{4+}$ = 22 - 4 = 18
The element is potassium. The number of electrons are 19. The number of electrons in $K^{+}$ = 19 - 1 = 18

The isoelectronic groups are:

$He,Be^{2+},Li^{+}$

$N^{3-},Mg^{2+}$

$S^{2-},Ti^{4+},K^{+}$

7 0

3 years ago

A certain reaction with an activation energy of 185 kJ/mol was run at 505 K and again at 525 K . What is the ratio of f at the h

frosja888 [35]

Answer:

The ratio of f at the higher temperature to f at the lower temperature is 5.356

Explanation:

Given;

activation energy, Ea = 185 kJ/mol = 185,000 J/mol

final temperature, T₂ = 525 K

initial temperature, T₁ = 505 k

Apply Arrhenius equation;

$Log(\frac{f_2}{f_1} ) = \frac{E_a}{2.303 \times R} [\frac{1}{T_1} -\frac{1}{T_2} ]$

Where;

$\frac{f_2}{f_1}$ is the ratio of f at the higher temperature to f at the lower temperature

R is gas constant = 8.314 J/mole.K

$Log(\frac{f_2}{f_1} ) = \frac{E_a}{2.303 \times R} [\frac{1}{T_1} -\frac{1}{T_2} ]\\\\Log(\frac{f_2}{f_1} ) = \frac{185,000}{2.303 \times 8.314} [\frac{1}{505} -\frac{1}{525} ]\\\\Log(\frac{f_2}{f_1} ) = 0.7289\\\\\frac{f_2}{f_1} = 10^{0.7289}\\\\\frac{f_2}{f_1} = 5.356$