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3 years ago

Why does the octet rule not always refer to a stable arrangement of eight valence electrons

Chemistry

1 answer:

bearhunter [10]3 years ago

4 0

Answer:

Explanation:

The octet rule does not always refer to a stable arrangement of eight valence electrons because there are some element that do not have eight valence electrons yet they are stable. for example;

i) Helium, It has two valence electrons and it is a stable gas.

ii) Boron triflouride (BF3); it has six valence electrons (deficit valence electron) yet it is also stable.

iii) Phosphorus pentachloride (PCl5); it has more than eight valence electron and it is also stable.

For these few reasons it is not always advisable to say octet arrangement refer to stable eight valence electrons.

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Given 4.80g of ammonium carbonate, find:

V125BC [204]

Answer:

1) 0.05 mol.

2) 0.1 mol.

3) 0.05 mol.

4) 0.4 mol.

5) 2.4 x 10²³ molecules.

Explanation:

1) Number of moles of the compound:

no. of moles of ammonium carbonate = mass/molar mass = (4.80 g)/(96.09 g/mol) = 0.05 mol.

2) Number of moles of ammonium ions :

Ammonium carbonate is dissociated according to the balanced equation:

(NH₄)₂CO₃ → 2NH₄⁺ + CO₃²⁻.

It is clear that every 1.0 mole of (NH₄)₂CO₃ is dissociated to produce 2.0 moles of NH₄⁺ ions and 1.0 mole of CO₃²⁻ ions.

∴ The no. of moles of NH₄⁺ ions in 0.05 mol of (NH₄)₂CO₃ = (2.0)(0.05 mol) = 0.1 mol.

3) Number of moles of carbonate ions :

Ammonium carbonate is dissociated according to the balanced equation:

(NH₄)₂CO₃ → 2NH₄⁺ + CO₃²⁻.

It is clear that every 1.0 mole of (NH₄)₂CO₃ is dissociated to produce 2.0 moles of NH₄⁺ ions and 1.0 mole of CO₃²⁻ ions.

∴ The no. of moles of CO₃²⁻ ions in 0.05 mol of (NH₄)₂CO₃ = (1.0)(0.05 mol) = 0.05 mol.

4) Number of moles of hydrogen atoms:

Every 1.0 mol of (NH₄)₂CO₃ contains:

2.0 moles of N atoms, 8.0 moles of H atoms, 1.0 mole of C atoms, and 3.0 moles of O atoms.

∴ The no. of moles of H atoms in 0.05 mol of (NH₄)₂CO₃ = (8.0)(0.05 mol) = 0.4 mol.

5) Number of hydrogen atoms:

It is known that every mole of a molecule or element contains Avogadro's number (6.022 x 10²³) of molecules or atoms.

Using cross multiplication:

1.0 mole of H atoms contains → 6.022 x 10²³ atoms.

0.4 mole of H atoms contains → ??? atoms.

∴ The no. of atoms in 0.4 mol of H atoms = (6.022 x 10²³ molecules)(0.4 mole)/(1.0 mole) = 2.4 x 10²³ molecules.

8 0

3 years ago

g Where, approximately, is the negative pole on each of these molecules? Lewis structure for C O F 2. A central C atom is single

seropon [69]

The molecule with higher dipole moment is COFH because the geometry of the molecule in the COF2 nearly cancel the dipolar moment of each other. To be more clear:

The dipolar moment is the vectorial sum of all bond moments in the molecule or dipolar moment of each bond. The dipolar moment of a molecule with three or more atoms is determined by bond polarity as their geometry.

COF2 has a trigonal planar structure which are symmetric. The electronegativity of oxygen is slightly different regarding fluor. So as you can see in the image, the electronic density is specially displaced to the fluor atoms, but either to the oxygen atom.

COFH has a trigonal structure but differs from COF2 because there is an hydrogen who is donating it's electronic density, so in this zone the electronic density is less than over oxygen or fluor. That makes bond angles be different between them.

3 0

2 years ago

Read 2 more answers

How many carbon atoms are there in .500 mol of CO2?

AURORKA [14]

Answer: There are $3.011 \times 10^{23}$ atoms present in 0.500 mol of $CO_{2}$ .

Explanation:

According to the mole concept, there are $6.022 \times 10^{23}$ atoms present in 1 mole of a substance.

In a molecule of $CO_{2}$ there is only one carbon atom present. Therefore, number of carbon atoms present in 0.500 mol of $CO_{2}$ are as follows.

$1 \times 0.500 \times 6.022 \times 10^{23}\\= 3.011 \times 10^{23}$

Thus, we can conclude that there are $3.011 \times 10^{23}$ atoms present in 0.500 mol of $CO_{2}$ .

6 0

2 years ago

Explain how matter changes from one state to another such as liquid

beks73 [17]

Answer:

When heated or cooled, matter can transform from one state to another. When you heat ice (a solid), it turns into water (a liquid). MELTING is the term for this transformation. When water is heated, it becomes steam (a gas).

Explanation:

i hope thats the answer you want

8 0

1 year ago

Conserving water can save money while protecting the environment. True or False

blagie [28]

Answer: The given statement is true.

Explanation:

Water is a natural resource present in the nature and it is very precious as life without it is impossible.

So, when we unnecessarily use water then it means we are wasting a natural resource that cannot be reproduced again by human beings.

Therefore, more we are able to conserve water more we can protect other human life's and environment also.

If there is shortage of water then its prices will go high and hence we need to pay more for it.

Thus, we can conclude that the statement conserving water can save money while protecting the environment, is true.

3 0

3 years ago

Read 2 more answers