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2 years ago

Calculate the pH of the following solutions at 298 K.

Chemistry

1 answer:

Minchanka [31]2 years ago

6 0

The term pH has to do with the hydrogen ion concentration of a solution.

The term pH has to do with the hydrogen ion concentration of a solution. Let us now proceed the pH of the solutions;

a) pH of HCl = -log(0.25) = 0.62

b) pH of H2SO4 = -log(0.15) = 0.82

c) We have to set up an ICE table here;

C6H5COOH + H2O ⇄ C6H5COO- + H^+

I 0.15 0 0

C -x +x +x

E 0.15 -x x x

Ka = [C6H5COO-] [ H^+]/[C6H5COOH]

6.4 x 10^-5 = x^2/0.15 - x

6.4 x 10^-5(0.15 - x) = x^2

9.6 * 10^-6 - 6.4 x 10^-5x = x^2

x^2 + 6.4 x 10^-5x - 9.6 * 10^-6 = 0

x=0.003 M

Hence;

[C6H5COO-] = [ H^+] = x = 0.003 M

pH = - log[0.003 M] = 2.5

d) [OH-] [H^+] = 1.0 x 10-14 mol2 dm-6

[H^+] = 1.0 x 10-14 mol2 dm-6/ 0.10 mol dm-3

[H^+] = 1 * 10^-13 M

pH= - log[1 * 10^-13 M] = 13

Learn more about pH of a solution:brainly.com/question/15289741

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Calculate the number of grams of solute in 814.2mL of 0.227 M calcium acetate

kiruha [24]

Answer:

Mass = 29.23 g

Explanation:

Given data:

Volume of solution = 814.2 mL 814.2/1000 = 0.8142 L)

Molarity of solution = 0.227 M

Mass of solute in gram = ?

Solution:

Molarity = number of moles / volume in L

By putting values,

0.227 M = number of moles / 0.8142 L

Number of moles = 0.227 M × 0.8142 L

Number of moles = 0.184 mol

Mass in gram:

Mass = number of moles × molar mass

Molar mass of calcium acetate = 158.17 g/mol

Mass = 0.184 mol × 158.17 g/mol

Mass = 29.23 g

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3 years ago

Which of the following substances is most likely to be a liquid at room temperature?

FromTheMoon [43]

The answer is: hydrogen peroxide, H2O2.

H₂O₂(hydrogen peroxide) is pale blue, clear, inorganic liquid.

It is liquid because hydrogen bonds between molecules.

Hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (H), covalently bound to a highly electronegative atom such as flourine (F), oxygen (O) and nitrogen (N) atoms.

Because of hydrogen bonds, hydrogen peroxide has higher melting and boiling temperatures than other molecules.

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3 years ago

Read 2 more answers

How much energy is required to raise the temperature of 10.6 grams of gaseous neon from

Alona [7]

Answer:

Approximately $1.95 \times 10^{2}\; \rm J$ .

Explanation:

Look up the specific heat of gaseous neon:

$c = 1.03 \; \rm J \cdot g^{-1} \cdot K^{-1}$ .

Calculate the required temperature change:

$\Delta T = (37.9 - 20.0)\; \rm K = 17.9\; \rm K$ .

Let $m$ denote the mass of a sample of specific heat $C$ . Energy required to raise the temperature of this sample by $\Delta T$ :

$Q = c \cdot m \cdot \Delta T$ .

For the neon gas in this question:

$c = 1.03\; \rm J \cdot g^{-1}\cdot K^{-1}$ .
$m = 10.6\; \rm g$ .
$\Delta T = (37.9 - 20.0)\; \rm K = 17.9\; \rm K$ .

Calculate the energy associated with this temperature change:

$\begin{aligned}Q &= c \cdot m \cdot \Delta T \\ &= 1.03\; \rm J \cdot g^{-1}\cdot K^{-1} \times 10.6\; \rm g \times 17.9\; \rm K \\ &\approx 1.95 \times 10^{2}\; \rm J\end{aligned}$ .

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3 years ago

A cylinder with a moving piston expands from an initial volume of 0.250 L against an external pressure of 2.00 atm. The expansio

kondor19780726 [428]

Answer:

The final volume of the cylinder is 1.67 L

Explanation:

Step 1: Data given

Initial volume = 0.250 L

external pressure = 2.00 atm

Expansion does 288 J of work on the surroundings

Step 2: Definition of reversible work:

Wrev = -P(V2-V1) = -288 J

The gas did work, so V2>V1 (volume expands) and the work has a negative sign.(Wrev<0)

V2 = (-Wrev/P) + V1

⇒ with Wrev = reverse work (in J)

⇒ with P = the external pressure (in atm)

⇒ with V1 = the initial volume

We can see that your pressure is in atm and energy in J

To convert from J to L * atm we should use a convenient conversion unit using the universal gas constants :

R = 8.314472 J/mol *K and R= 0.08206 L*atm/K*mol

V2 =- (-288 J * (0.08206 L*atm/K*mol /8.314 J/mol *K))/2.00 atm + 0.250L

V2 = 1.67 L

The final volume of the cylinder is 1.67 L

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Answer:

The atoms share some of their outer electrons so that each atom has a stable noble gas arrangement.

Explanation:

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