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4 years ago

HELP!!!

2 answers:

7 0

Answer: The concentration of hydronium ions in a solution is $2.5\times 10^{-5}$ and the concentration of hydroxide ion concentration is $4\times 10^{-10}$

Explanation:

pH is defined as negative logarithm of hydrogen ion concentration. It is basically defined as the power of hydrogen ions in a solution.

Mathematically,

$pH=-\log[H^+]$

pH of the solution = 4.6

Putting values in above equation, we get:

$4.6=-\log[H^+]$

$[H^+]=antilog(-4.6)$

$[H^+]=2.5\times 10^{-5}$

We are given:

pH of the solution = 4.6

To calculate the hydroxide ion concentration of the solution, we need to determine the pOH of the solution first. And to calculate that we use the equation:

$pH+pOH=14\\pOH=14-4.6=9.4$

pOH is defined as negative logarithm of hydroxide ion concentration. It is basically defined as the power of hydroxide ions in a solution.

Mathematically,

$pOH=-\log[OH^-]$

pOH of the solution = 9.4

Putting values in above equation, we get:

$9.4=-\log[OH^-]$

$[OH^-]=antilog(-9.4)$

$[OH^-]=4\times 10^{-10}$

Hence, the concentration of hydronium ions in a solution is $2.5\times 10^{-5}$ and the concentration of hydroxide ion concentration is $4\times 10^{-10}$

vladimir2022 [97]4 years ago

4 0

Answer:

2.5 × 10⁻⁵ M H₃O⁺ and 4.0 × 10⁻¹⁰ M OH⁻.

Explanation:

∵ pH = - log[H₃O⁺]

∴ 4.6 = - log[H₃O⁺].

∴ log[H₃O⁺] = - 4.6.

∴ [H₃O⁺] = 2.51 x 10⁻⁵.

∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.

[H₃O⁺] = 2.51 x 10⁻⁵ M.

∴ [OH⁻] = 10⁻¹⁴/[H₃O⁺] = 10⁻¹⁴/(2.51 x 10⁻⁵ M) = 3.98 × 10⁻¹⁰ M ≅ 4.0 × 10⁻¹⁰ M.

So, the right choice is: 2.5 × 10⁻⁵ M H₃O⁺ and 4.0 × 10⁻¹⁰ M OH⁻.

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True or false : rocks have different properties such as hardness and texture

harkovskaia [24]

Answer:

true

Explanation:

Rocks have different properties such as hardness and texture

Metamorphic rocks form when heat and pressure cause sedimentary or igneous rocks to recrystallize into new rock.

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6 0

4 years ago

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Plz help thank you!!!

Furkat [3]

Answer:

1. Covalent Bond

2. Ionic Bond

Explanation:

Covalent bonds are defined as the bond in which sharing of electrons takes place between atoms. The sharing of electrons is in equal number so that it form a stable balance of attraction and repulsion between atoms. In the given example of CO2 (first image) oxygen is sharing equal number of electrons with carbon to form a stable bond called covalent bond.

Ionic bonds are formed when valence electrons are transferred to other atoms and form oppositely charged ions. In ionic bond formation, the atoms that gain electrons become negatively charged and the atoms that loses electrons become positively charged. In the given example of Ca Cl2, Ca is also giving its 2 valence electrons to each Cl and there is no stable balance of attraction and repulsion between atoms.

Hence, the correct answer is:

1. Covalent Bond

2. Ionic Bond

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3 years ago

10g of sugar is dissolved by water to make 200g of solution of sugar. What is the percent by mass of the solution?

Scorpion4ik [409]

Explanation:

In sugar solution 200 g has sugar 10 g

In sugar solution 100 g has sugar 10/200 × 100

= 5 %w/w

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3 years ago

A 1-liter solution contains 0.494 M hydrofluoric acid and 0.371 M potassium fluoride. Addition of 0.408 moles of hydrochloric ac

UkoKoshka [18]

Answer:

Option f: an addition of HCl will exceed the buffer capacity. The option d is also correct since it is a consequence of the option f.

Explanation:

The pH of the buffer solution before the addition of HCl is:

$pH = pKa + log(\frac{[KF]}{[HF]})$

$pH = -log(6.8 \cdot 10^{-4}) + log(\frac{0.371}{0.494}) = 3.04$

The hydrochloric acid added will react with the potassium fluoride as follows:

H₃O⁺(aq) + F⁻(aq) ⇄ HF(aq) + H₂O(l)

The number of moles (η) of potassium fluoride (KF) and the HF before the addition of HCl is:

$\eta_{KF}_{i} = C_{KF}*V = 0.371 M*1 L = 0.371 mol$

$\eta_{HF}_{i} = C_{HF}*V = 0.494 M*1 L = 0.494 moles$

The number of moles of the HCl added is 0.408 moles. Since the number of moles of HCl is bigger thant the number of moles of KF, the moles of HCl that remains after the reaction is:

$\eta_{HCl} = \eta_{HCl} - \eta_{KF}_{i} = 0.408 moles - 0.371 moles = 0.037 moles$

Hence, the KF is totally consumed after the reaction with HCl and thus, exceding the buffer capacity.

We can calculate the pH after the addition of HCl:

HF(aq) + H₂O(l) ⇄ F⁻(aq) + H₃O⁺(aq) (1)

The number of moles of HF after the reaction of KF with HCl is:

$\eta_{HF} = 0.494 moles + (0.408 moles - 0.371 moles) = 0.531 moles$

And the concentration of HF after the reaction of KF with HCl is is:

$C_{HF} = \frac{\eta_{HF}}{V} = \frac{0.531 moles}{1 L} = 0.531 moles/L$

Now, from the equilibrium of equation (1) we have:

$Ka = \frac{[H_{3}O^{+}][F^{-}]}{[HF]}$

$Ka = \frac{x^{2}}{0.531 - x}$ (2)

By solving equation (2) for x we have:

x = 0.0187

Finally, the pH after the addition of HCl is:

$pH = -log (H_{3}O^{+}) = -log (0.0187) = 1.73$

Therefore, the addition of HCl will exceed the buffer capacity and thus, lower the pH by several units. The correct option is f: an addition of HCl will exceed the buffer capacity. The option d is also correct since it is a consequence of the option f.

I hope it helps you!

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4 years ago

A weather balloon has a volume of 52.5 liters at a temperature of 295 K. The balloon is released and rises to an altitude where

Goryan [66]

So you have a balloon rising through the atmosphere. use the formula p1/v1=p2/v2 and add the variables into the equation, leaving 295/52.5=252/x. multiply 252 by 52.5 and divide that number by 295.
52.5*252=13230. divide by 295 =44.9 L

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3 years ago

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