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Musya8 [376]
2 years ago
14

An atom has the following electron configuration . 1s^ 2 2s^ 2 2p^ 6 3s^ 2 3p^ 6 4s^ 2 How many valence electrons does this atom

have ?
2
3
5
11
Chemistry
1 answer:
stepan [7]2 years ago
5 0
It’s 2 because it’s the number of row it is in; the element is calcium in row 2
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A. There is no movement
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5 0
2 years ago
In the "Méthode Champenoise," grape juice is fermented in a wine bottle to produce sparkling wine. The reaction is the following
prohojiy [21]

Answer:

The pressure inside the wine bottle at 21 °C is 4.8 · 10² atm

Explanation:

Hi there!

We know that 1 mol of CO₂ is produced per mol of produced ethanol.

If the final concentration of ethanol is 13%, let´s calculate how many moles of ethanol are present at that concentration.

A concentration of 13% means that in 100 ml of solution, 13 ml is dissolved ethanol. We have 754 ml of solution, then, the volume of ethanol will be:

754 ml solution · (13 ml ethanol/100 ml solution) = 98 ml ethanol

With the density, we can calculate the mass of ethanol present:

density = mass/ volume

0.79 g/ml = mass / 98 ml

mass = 0.79 g/ml · 98 ml

mass = 77 g

The molar mass of ethanol is 46.07 g/mol, then 77 g of ethanol is equal to:

77 g · (1 mol/46.07 g) = 1.7 mol

Then, the number of moles of CO₂ produced will be 1.7 mol.

Using the equation of the ideal gas law, we can calculate the pressure of CO₂:

P = nRT/V

Where:

P = pressure

n = number of moles

R = ideal gas constant

T = temperature

V = volume

The volume will be the headspace of the bottle (840 ml - 754 ml) 86 ml = 0.086 l.

The temperature in kelvin will be: 21 + 273 = 294 K

The gas constant is 0.082 l atm / K mol

Then:

P = (1.7 mol · 0.082 l atm/K mol · 294 K)/ 0.086 l

P = 4.8 · 10² atm

The pressure inside the wine bottle at 21 °C is 4.8 · 10² atm

5 0
2 years ago
Describe what human Microbiome is: HELP ASP!!!
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Answer:

The microbiome is defined as the collective genomes of the microbes (composed of bacteria, bacteriophage, fungi, protozoa and viruses) that live inside and on the human body. We have about 10 times as many microbial cells as human cells.

Explanation:

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7 0
3 years ago
The following reaction shows the products when sulfuric acid and aluminum hydroxide react.
scoray [572]

Leftover: approximately 11.73 g of sulfuric acid.

<h3>Explanation</h3>

Which reactant is <em>in excess</em>?

The theoretical yield of water from Al(OH)₃ is lower than that from H₂SO₄. As a  result,

  • Al(OH)₃ is the limiting reactant.
  • H₂SO₄ is in excess.

How many <em>moles</em> of H₂SO₄ is consumed?

Balanced equation:

2 Al(OH)₃ + 3 H₂SO₄ → Al₂(SO₄)₃ + 6 H₂O

Each mole of Al(OH)₃ corresponds to 3/2 moles of H₂SO4. The formula mass of Al(OH)₃ is 78.003 g/mol. There are 15 / 78.003 = 0.19230 moles of Al(OH)₃ in the five grams of Al(OH)₃ available. Al(OH)₃ is in excess, meaning that all 0.19230 moles will be consumed. Accordingly, 0.19230 × 3/2 = 0.28845 moles of H₂SO₄ will be consumed.

How many <em>grams</em> of H₂SO₄ is consumed?

The molar mass of H₂SO₄ is 98.076 g.mol. The mass of 0.28845 moles of H₂SO₄ is 0.28845 × 98.076 = 28.289 g.

How many <em>grams</em> of H₂SO₄ is in excess?

40 grams of sulfuric acid H₂SO₄ is available. 28.289 grams is consumed. The remaining 40 - 28.289 = 11.711 g is in excess. That's closest to the first option: 11.73 g of sulfuric acid.

6 0
2 years ago
Which of the following lists of elements are in the same PERIOD? *
yuradex [85]
Ca, V, Cu, Kr
Remember a period is a the horizontal rows in the Periodic Table.

5 0
3 years ago
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