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4 years ago

How to determine how many valence electrons an element has?

1 answer:

8 0

Usually (ignoring transition metals, as they kinda get trickier), the element's valency can be found out by its group (column) number. Usually, we ignore the transition metal block while counting these columns, so Aluminium is in group 3, for example. Since Aluminium is in group 3, it has 3 valence electrons.

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Using the equation 40kJ+2SO3(g)-->2SO2(g) + O2(g), if pressure is added what way

Ad libitum [116K]

In an equation, 40kJ + 2SO₃ (g) -->2SO₂(g) + O₂(g), if pressure added, the equilibrium shifts to the left side of the reaction because it has fewer moles of gas.

<h3>What is Le Ch atelier's principle?</h3>

Le Ch atelier's principle states that if the pressure is added in a nay reaction, then the equilibrium will be shifted toward the side where there are fewer atoms.

In this case, there are fewer moles on the left side.

Thus, when pressure is added, the equilibrium shift to the left side due to Le Ch atelier's principle.

Learn more about Le Ch atelier's principle

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6 0

2 years ago

What is a covalent bond

diamong [38]

Answer:

Covalent bonds involve the sharing of electron pairs between atoms. Electron pairs shared between atoms of equal or very similar electronegativity constitute a nonpolar covalent bond (e.g., H–H or C–H), while electrons shared between atoms of unequal electronegativity constitute a polar covalent bond (e.g., H–O).

Explanation:

8 0

3 years ago

Look at the picture and select the answer quicly

Mars2501 [29]

I believe c. I hope it helps :)

6 0

3 years ago

What is the pH of a 0.1 M HCl solution?

sesenic [268]

Answer:

The pH of the solution is 1.00

Explanation:

The pH gives us an idea of the acidity or basicity of a solution. More precisely, it indicates the concentration of H30 + ions present in said solution. The pH scale ranges from 0 to 14: from 0 to 7 corresponds to acid solutions, 7 neutral solutions and between 7 and 14 basic solutions. It is calculated as:

pH = -log (H30 +)

The concentration of the H30+ ions is 0,1M:

pH= -log (0,1)

8 0

3 years ago

If 24.3 g of NO and 13.8 g of O₂ are used to form NO₂, how many moles of excess reactant will be left over?2 NO (g) + O₂ (g) → 2

zhuklara [117]

Explanation:

2 NO (g) + O₂ (g) ----> 2 NO₂ (g)

24.3 g of NO are reacting with 13.8 g of O₂. First we can convert the mass of theses samples into moles using their molar masses.

molar mass of O = 16.00 g/mol

molar mass of N = 14.01 g/mol

molar mass of NO = 16.00 g/mol + 14.01 g/mol

molar mass of NO = 30.01 g/mol

molar mass of O₂ = 2 * 16.00 g/mol

molar mass of O₂ = 32.00 g/mol

moles of NO = 24.3 g * 1 mol/(30.01 g)

moles of NO = 0.810 moles

moles of O₂ = 13.8 g * 1 mol/(32.00 g)

moles of O₂ = 0.431 moles

Now, to determine the limiting reactant or the excess reactant we can find the number of moles of O₂ that will react with 0.810 moles of NO and the number of moles of NO that will react with 0.431 moles of O₂.

According to the coefficients of the reaction 2 moles of NO will react with 1 mol of O₂. Let's use that relationship to find the limiting reagent.

2 moles of NO = 1 mol of O₂

moles of O₂ = 0.810 moles of NO * 1 mol of O₂/(2 moles of NO)

moles of O₂ = 0.405 moles

moles of NO = 0.431 moles of O₂ * 2 moles of NO/(1 mol of O₂)

moles of NO = 0.862 moles

We found that we need 0.405 moles of O₂ to completely react with 0.810 moles of NO. Or, we need 0.862 moles of NO to completely react with ours 0.431 moles of NO.

We can say that NO is limiting our reaction and O₂ is in excess.

Only 0.405 moles of O₂ will react with 0.810 moles of NO. But we had 0.431 moles of it. Let's find the excess.

Excess of O₂ = 0.431 moles - 0.405 moles

Excess of O₂ = 0.026 moles

Answer: 0.026 moles is the number of moles of oxygen that will be left over.

4 0

1 year ago