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3 years ago

Chapter 2 test chemistry

1 answer:

6 0

Im sorry but Chapter 2 test chemistry doesnt sound much like a question can you be more specific thanks ik u can be more specififc!

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PLEASEEEEEE answer these 2 questions!! I WILL GIVE BRAINLIEST AND POINTS

Olegator [25]

Answer: B then D

Explanation:

8 0

3 years ago

Find the pH of a 0.100 molar H2C6O6 solution with ka, where KA is equal 8.0×10–5

lubasha [3.4K]

The pH of the solution is 2.54.

Explanation:

pH is the measure of acidity of the solution and Ka is the dissociation constant. Dissociation constant is the measure of concentration of hydrogen ion donated to the solution.

The solution of C₆H₂O₆ will get dissociated as C₆HO₆ and H+ ions. So the molar concentration of 0.1 M is present at the initial stage. Lets consider that the concentration of hydrogen ion released as x and the same amount of the base ion will also be released.

So the dissociation constant Kₐ can be written as the ratio of concentration of products to the concentration of reactants. As the concentration of reactants is given as 0.1 M and the concentration of products is considered as x for both hydrogen and base ion. Then the

$K_{a}=\frac{[H^{+}][HB] }{[reactant]}$

[HB] is the concentration of base.

$8 * 10^{-5} =\frac{x^{2} }{0.1}\\\\\\x^{2} = 8 * 10^{-5}*0.1$

$x^{2} = 0.08 * 10^{-4}\\ \\x = 0.283*10^{-2}$

Then

$pH = - log [x] = - log [ 0.283 * 10^{-2}]\\ \\pH = 2 + 0.548 = 2.54$

So the pH of the solution is 2.54.

4 0

3 years ago

Which of the follow describes what happpens to the kinetic energy of water when it changes from the solid state to a liquid stat

Anestetic [448]

Answer:

Kinetic energy increases.

Explanation:

In a solid, molecules do not have much room to move. They are very slow moving, which means that kinetic energy is low. In a liquid, molecules have more room to move. They are able to move faster than a solid, which means that kinetic energy is low.

From greatest to lowest kinetic energy:

gas, liquid, solid

7 0

3 years ago

TIMED PLS HELP AND WILL GIVE BRAINLIST

Strike441 [17]

Answer:

19.4 g of alum, will be its theoretical yield

Explanation:

The reaction is:

2 Al + 2 KOH + 4 H₂SO₄ + 22H₂O → 3H₂ + 2KAl(SO₄)₂•12H₂O

Let's determine the amount of acid.

M are the moles contained in 1 L of solution or it can be mmoles that are contained in 1 mL of solution

M = mmol /mL

M . mL = mmol

We replace: 8.3 mL . 9.9 M = 82.17 mmoles

We convert to moles: 82.17 mmol . 1 mol / 1000mmol = 0.082 moles

Ratio is 4:2

4 moles of sulfuric acid can make 2 moles of alum

By the way, 0.082 moles of acid may produce ( 0.082 . 2) /4 = 0.041085 moles.

We convert moles to mass:

Molar mass of alum is: 473.52 g/mol.

0.041085 moles . 473.52 g/mol = 19.4 g

6 0

3 years ago

A gas at constant temperature has a pressure of 404.6 kPa with a volume of 12 ml. If the volume changes to 43ml, what is the new

blagie [28]

Answer:

The answer is

Explanation:

The new pressure can be found by using the formula for Boyle's law which is

$P_1V_1 = P_2V_2$

Since we are finding the new pressure

$P_2 = \frac{P_1V_1}{V_2} \\$

404.6 kPa = 404600 Pa

From the question we have

$P_2 = \frac{404600 \times 12}{43} = \frac{4855200}{43} \\ = 112911.6279... \\ = 112912$

We have the final answer as

Hope this helps you

4 0

3 years ago