All categories

3 years ago

What is the octet rule and how is it used in covalent bonding?

1 answer:

4 0

The octet rule is the fundamental explanation to give the reasons as for why atoms would undergo complex molecular and ionic arrangements, by sharing or transferring valence or bonding electrons between atoms in a compound.

It states that atoms would need to have the maximum number of electrons in their valence shell to be inactive and stable. Thus atoms would tend to bond to other atoms to achieve this Lower energy and stability.

They do this by sharing between electrons between atoms as in covalent bonds.

You might be interested in

Which element has chemical properties that are most similar to those of calcium?

iris [78.8K]

I think the answer is (1) Co. Because the element of Cobalt also has 2 electrons at the outer layer which is the same as Calcium. And the outer layer is an important factor which can affect the property of an element.

3 0

4 years ago

Read 2 more answers

Which of the following are not single-displacement reactions?

Goshia [24]

Answer:

$\boxed{\text{B and C }}$

Explanation:

In a single-displacement reaction, one element exchanges partners with another element in a compound.

$\textbf{A. } \rm Fe + 2HCl \longrightarrow FeCl_2 + H_2$

This is a single-displacement reaction, because the element Fe exchanges partners with H in HCl.

$\textbf{B. } \rm KOH + HNO_3 \longrightarrow H_2O + KNO_3$

This is not a single-displacement reaction, because it is a reaction between two compounds.

This is a double displacement reaction in which the K⁺ and H⁺ cations change partners with the anions.

$\textbf{C. } \rm Na_2S + 2HCl \longrightarrow 2NaCl + H_2S$

This is not a single-displacement reaction. It is another double displacement reaction, in which the Na⁺ and H⁺ cations change partners with the anions.

$\textbf{D. } \rm Ca + 2HOH \longrightarrow Ca(OH)_2 + H_2$

This is a single-displacement reaction, because the element Ca exchanges partners with H in H₂O.

$\boxed{\textbf{B and C }}$ are not single-displacement reactions.

6 0

3 years ago

Calcule a variação da entalpia dessa reação ( 2 NH3 (g) ---> CO(NH2)2 (s) + H2O (L) ) a partir das seguintes equações termoqu

Nitella [24]

ΔH = +438 kJ

We have three equations:

(I) N₂ + 3H₂ → 2NH₃; ΔH = -92 kJ

(II) H₂ +½O₂ → H₂O; ΔH = -286 kJ

(III) CO(NH₂)₂ + ³/₂O₂ → CO₂ + 2H₂O + N₂; ΔH = -632 kJ

From these, we must devise the target equation:

(IV) 2NH₃ + CO₂ → CO(NH₂)₂ + H₂O; ΔH = ?

_________________________________

The target equation has 2NH₃ on the left, so you reverse equation (I).

When you reverse an equation, you reverse the sign of its ΔH.

(V) 2NH₃ → N₂ + 3H₂; ΔH = +92 kJ

Equation (V) has 1N₂ on the right, and that is not in the target equation.

You need an equation with 1N₂ on the left.

Reverse Equation (III).

(VI) CO₂ + 2H₂O + N₂ → CO(NH₂)₂ + ³/₂O₂; ΔH = +632 kJ

Equation (VI) has ³/₂O₂ on the right, and that is not in the target equation.

You need ³/₂O₂ on the left.

Multiply Equation (II) by three.

When you multiply an equation by three, you multiply its ΔH by three.

(VII) 3H₂ +³/₂O₂ → 3H₂O; ΔH = -286 kJ

Now, you add equations (V), (VI), and (VII), cancelling species that appear on opposite sides of the reaction arrows.

When you add equations, you add their ΔH values.

_______________________________________

We get the target equation (IV):

(V) 2NH₃ → N₂ + 3H₂; ΔH = + 92 kJ

(VI) CO₂ + 2H₂O + N₂ → CO(NH₂)₂ + ³/₂O₂; ΔH = +632 kJ

(VII) 3H₂ +³/₂O₂ → 3H₂O; ΔH = -286 kJ

(IV) 2NH₃ + CO₂ → CO(NH₂)₂ + H₂O; ΔH = +438 kJ

7 0

3 years ago

Why is concentrated sodium hydroxide preferred than water

mariarad [96]

Answer:

Sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns. It is highly soluble in water, and readily absorbs moisture and carbon dioxide from the air. It forms a series of hydrates NaOH·nH

2O.[11] The monohydrate NaOH·H

2O crystallizes from water solutions between 12.3 and 61.8 °C. The commercially available "sodium hydroxide" is often this monohydrate, and published data may refer to it instead of the anhydrous compound.

As one of the simplest hydroxides, sodium hydroxide is frequently utilized alongside neutral water and acidic hydrochloric acid to demonstrate the pH scale to chemistry students.[12]

Sodium hydroxide is used in many industries: in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents, and as a drain cleaner. Worldwide production in 2004 was approximately 60 million tons, while demand was 51 million tons.[13]

8 0

3 years ago

If 9.5 × 10²⁵ molecules of CO₂ are produced in a combustion reaction, what is the mass in kg of CO₂ that is produced?

Leno4ka [110]

Answer:

6.9428 kg of CO2

Explanation:

1) Use Avogadro's number that states 1 mole = 6.022 x 10^23 particles. Convert 9.5 x 10^25 molecules into moles.

9.5 x 10^25 CO2 molecules $x\frac{1 mole CO2}{6.022 x 10^23}$ = 157.75 moles CO2