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2 years ago

Which of the following formulas is used to determine the pH of a solution?

Chemistry

1 answer:

hjlf2 years ago

3 0

Answer:

pH = -log[H+]

Explanation:

The pH of a solution is simply the negative logarithm of the hydrogen ion concentration. It can thus be written mathematically as:

pH = -log[H+]

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Calculate the solubility of CaF2 in g/L (Ksp = 4.0 x 10-8). 2. What is the pH of a solution containing a hydrogen ion concentrat

Pepsi [2]

Answer:

$\large \boxed{1. \text{ 0.17 g/L; 2. 3.52; 3. Cl; 4. (a) +3; (b) +4; (c) +6}}$

Explanation:

1. Solubility of CaF_2

(a) Molar solubility

CaF₂ ⇌ Ca²⁺ + 2F⁻

$K_{\text{sp }} = \text{[Ca$^{2+}$]}\text{[F$^{-}$]}^{2}= 4.0 \times 10^{-8}\\s(2s)^{2}=4.0 \times 10^{-8}\\4s^{3} = 4.0 \times 10^{-8}\\s^{3} = 1.0 \times 10^{-8}\\s =2.2 \times 10^{-3}\text{ mol/L}$

(b) Mass solubility

$\text{Solubility} = 2.2 \times 10^{-3} \text{ mol/L} \times \dfrac{\text{78.07 g}}{\text{1 L }} = \text{0.17 g/L}\\\\\text{The solubility of CaF$_{2}$ is $\large \boxed{\textbf{0.17 g/L}}$}$

2. pH

pH = -log [H⁺] = -log(3.0 × 10⁻⁴) = 3.52

3. Oxidizing and reducing agents

Zn + Cl₂ ⟶ ZnCl₂

$\rm \stackrel{\hbox{0}}{\hbox{Zn}} + \stackrel{\hbox{0}}{\hbox{ Cl}_{2} }\longrightarrow \stackrel{\hbox{+2}}{\hbox{Zn}}\stackrel{\hbox{-1}}{\hbox{Cl}_{2}}$

The oxidation number of Cl has decreased from 0 to -1.

Cl has been reduced, so Cl is the oxidizing agent.

4. Oxidation numbers

(a) Al₂O₃

$\stackrel{\hbox{$\mathbf{+3}$}}{\hbox{Al}_{2}}\stackrel{\hbox{-2}}{\hbox{O}_{3}}$

1O = -2; 3O = -6; 2Al = +6; 1Al = +3

(b) XeF₄

$\stackrel{\hbox{$\mathbf{+4}$}}{\hbox{Xe}}\stackrel{\hbox{-1}}{\hbox{F}_{4}}$

1F = -1; 4F = -4; 1 Xe = +4

(c) K₂Cr₂O₇

$\stackrel{\hbox{${+1}$}}{\hbox{K}_{2}}\stackrel{\hbox{$\mathbf{+6}$}}{\hbox{Cr}_{2}}\stackrel{\hbox{-2}}{\hbox{O}_{7}}$

1K = +1; 2K = +2; 1O = -2; 7O = -14

+2 - 14 = -12

2Cr = + 12; 1 Cr = +6

8 0

3 years ago

Need help with this chemistry homework

Elza [17]

Answer:

10.0 ml and 35.0ml respectively

Explanation:

if A=10.0ml let B be x

Now,

Lets assume the pan is balanced

then,

x = 10.0 ml

Therefore B= 10.0 ml

[Repeat the same process in next question]

7 0

2 years ago

The magma flows slowly down the slope of the volcano. Which property of magma does the sentence describe?

kifflom [539]

Viscosity is the rate at which liquids flow.

7 0

3 years ago

Examine the incomplete statement.

hjlf

Answer: Option (c) is the correct answer.

Explanation:

In liquids, molecules are held by slightly less strong intermolecular forces of attraction as compared to solids.

Hence, molecules of a liquid are able to slide past each other as they have more kinetic energy than the molecules of a solid.

As a result, liquids are able to occupy the shape of container in which they are placed. Also, liquids have fixed volume but no fixed shape.

Thus, we can conclude that liquids have a variable shape and a fixed volume.

5 0

3 years ago

Read 2 more answers

A cube of steel with a mass of 150 grams is heated from 60°C to 150°C.

yan [13]

Answer:

The energy lost by the water is given by:

where

m = 3.0 kg = 3000 g is the mass of water

Cs = 4.179 J/g•°C is the specific heat

is the change in temperature

Substituting,

The energy added to the aluminium is given by:

where

m = 0.30 kg = 300 g is the mass of aluminium

Cs = 0.900 J/g•°C is the specific heat

is the change in temperature

Substituting,

4. 42.9 g

The mass of the water sample is given by

where

is the heat added

is the temperature change

Cs = 4.179 J/g•°C is the specific heat

5. 115.5 J

The heat used to heat the copper is given by:

where

m = 5.0 g is the mass of copper

Cs = 0.385 J/g•°C is the specific heat

is the change in temperature

6. 0.185 J/g•°C

The specific heat of iron is given by:

where

Q = -47 J is the heat released by the iron

m = 10.0 g is the mass of iron

is the change in temperature

Substituting,

Explanation:

8 0

3 years ago