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3 years ago

What is the percent of oxygen by mass in a pure sample of fecr2o4? 1. 52% 2. 13% 3. 37% 4. 7.1% 5. 29%?

1 answer:

6 0

Let us suppose that we have 1 mol of FeCr2O4. I'm going to use approximate masses because I have no idea what your periodic table will say. Just put in the exact masses from your periodic table.

Fe = 56
Cr*2 = 2*52 = 104
O4 = 4*16 = 64
===========
Total = 56 + 104 + 64 = 224
The % oxygen = (64 / 224) * 100 = 28.5 % but none of your answers match this. Perhaps you are talking about Fe2(Cr2O4)3 The brackets make all the difference in the world.

Without going through all the detail I did before, The molecular mass is
Fe * 2 = 112
Cr * 6 = 312
O * 12 = 192
The total molecular mass = 616

The % Oxygen = (192 / 616) * 100 = 31% roughly. That answer isn't there either.

Let's wait and see who else answers.

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What are diatomic molecules and are they compounds? PLEASE ANSWER ASAP!!

Fantom [35]

Answer:

Diatomic molecules consist of two atoms that are chemically bonded. The two atoms can be the same or different chemical elements. As for whether or not they are compounds, there is not technically an answer. This is because all compounds are molecules, but not all molecules are compounds. For example diatomic molecules that comprise the chemical compounds nitric acid, carbon monoxide, and hydrogen chloride are made up of two different elements. As you can see, most diatomic molecules are not made up of the same kind of elements and not every diatomic molecule comprises a chemical compound.

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Explanation:

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3 years ago

Calculate the pH of a solution prepared by mixing: (Show your work for these calculations) pk of acetic acid is 4.75 a. two mole

kupik [55]

Answer:

Explanation:

To calculate pH you need to use Henderson-Hasselbalch formula:

pH = pka + log₁₀ $\frac{[A^-]}{[HA]}$

Where HA is the acid concentration and A⁻ is the conjugate base concentration.

The equilibrium of acetic acid is:

CH₃COOH ⇄ CH₃COO⁻ + H⁺ pka: 4,75

Where CH₃COOH is the acid and CH₃COO⁻ is the conjugate base.

Thus, Henderson-Hasselbalch formula for acetic acid equilibrium is:

pH = 4,75 + log₁₀ $\frac{[CH_{3}COO^-]}{[CH_{3}COOH]}$

a) The pH is:

pH = 4,75 + log₁₀ $\frac{[2 mol]}{[2 mol]}$

pH = 4,75

b) The pH is:

pH = 4,75 + log₁₀ $\frac{[2 mol]}{[1mol]}$

pH = 5,05

I hope it helps!

7 0

4 years ago

Determine the molecular formula of a compound that has a molar mass of 183.2 g/mol and an empirical formula of c2h5o2.

Tpy6a [65]

C6H15O6

Good luck and don't forget to rate or mark Brainliest :)

6 0

3 years ago

Read 2 more answers

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balandron [24]

B. .175

Hope it helps!

4 0

3 years ago

Identify and explain the process shown below. Name any two products obtained during this process and state their uses.

lapo4ka [179]

Answer:

This is heating limestone

Explanation:

Process:

limestone is heated strongly. After a while, the limestone begins to go cloudy. Test tube is heated too much that it is beginning to soften it. After removing limewater, test tube cools down, the pressure in the test tube drops and air pressure pushes the cold the liquid into the hot test tube with terrible result.

Products:

Limestone is also known as calcium carbonate and Limewater

Click on the link provided to show the video

https://youtu.be/RLL5rT_DeKc

or search heating calcium carbonate

you will find a video

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3 years ago