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3 years ago

What is the ground-state electron configuration of chlorine and the number of valence electrons in it?

Chemistry

1 answer:

SSSSS [86.1K]3 years ago

8 0

Explanation:

Chlorine is an element in group 7 on the periodic table.

It is the second element in this group of halogens

The element has a total of 17 electrons:

Ground state configuration = 1s² 2s² 2p⁶ 3s² 3p⁵

Valence electrons are the outermost shell electrons;

From the configuration: 3s² 3p⁵ is the valence shell

Number of electrons = 2 + 5 = 7

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How many milliliters of ammonium sulfate solution having a concentration of 0.218 M are needed to react completely with 62.6 ml

BartSMP [9]

Answer:

330 mL of (NH₄)₂SO₄ are needed

Explanation:

First of all, we determine the reaction:

(NH₄)₂SO₄ + 2NaOH → 2NH₃ + 2H₂O + Na₂SO₄

We determine the moles of base:

(First, we convert the volume from mL to L) → 62.6 mL . 1L/1000 mL = 0.0626L

Molarity . volume (L) = 2.31 mol/L . 0.0626 L = 0.144 moles

Ratio is 2:1. Therefore we make a rule of three:

2 moles of hydroxide react with 1 mol of sulfate

Then, 0.144 moles of NaOH must react with (0.144 .1) /2 = 0.072 moles

If we want to determine the volume → Moles / Molarity

0.072 mol / 0.218 mol/L = 0.330 L

We convert from L to mL → 0.330L . 1000 mL/1L = 330 mL

6 0

3 years ago

PLZ HELP ASAP

GrogVix [38]

Answer:

The second option

Explanation:

Speed is defined at the rate at which distance changes with time. It is scalar quantity and it is expressed as shown below:

Speed = $\frac{distance}{time}$

At constant speed the rate of change of distance with time is the same. On the second graph, this is noticeable. Both distance and time change at the same rate.

7 0

3 years ago

What are the 2 basic parts of an atom?

Lerok [7]

Answer:

nucleus and electrons

Explanation:

nucleus contains protons and neutrons

5 0

2 years ago

Read 2 more answers

if the volume of a gas contracted from 648 mL to 0.15L, what was its final pressure if it started at a pressure of 485 kpa

bija089 [108]

Answer:

2100 kPa

Explanation:

The temperature is constant, so the only variables are pressure and volume.

We can use Boyle’s Law.

p₁V₁ = p₂V₂ Divide both sides of the equation by V₂

p₂ = p₁ × V₁/V₂

p₁ = 485 kPa; V₁ = 648 mL

p₂ = ?; V₂ = 0.15 L = 150 mL Calculate p₂

p₂ = 485 × 648/150

p₂ = 2100 kPa

4 0

3 years ago

You placed a sample of a hydrate of calcium chloride (CaCl2) in a weighed test tube, and weighed the filled test tube.

ziro4ka [17]

Answer:

1. 5g

2. 2.3g

3. 2.7g

4. 0.02mol

5. 0.13mol

6. 7moles

Explanation:

From the question, the following were obtained:

Mass of empty tube = 13.5g

Mass of empty tube + hydrated salt = 18.5g

Mass of tube + anhydrous salt = 16.2g

1. Mass of empty tube = 13.5g

Mass of empty tube + hydrated salt = 18.5g

Mass of hydrated salt = 18.5 — Mass of empty tube

Mass of hydrated salt = 18.5 — 13.5 = 5g

2. Let us calculate the mass of the anhydrous salt.

Mass of tube + anhydrous salt = 16.2g

Mass of empty tube = 13.5g

Mass of anhydrous salt = 16.2 — Mass of empty tube = 16.2 — 13.5

Mass of anhydrous salt = 2.7g

Now we can calculate the mass of the water evolved as follows:

Mass of water = Mass of hydrated salt — Mass of anhydrous

Mass of water = 5 — 2.7 = 2.3g

3. Mass of empty tube = 13.5g

Mass of anhydrous salt = 16.2 — Mass of empty tube = 16.2 — 13.5

Mass of anhydrous salt = 2.7g

4. MM of CaCl2 = 40 +(2x35.5) = 40 + 71 = 111g

Mass of CaCl2 = 2.7g

Number of mole = Mass /Molar Mass

Number of mole of CaCl2 = 2.7/111 = 0.02mol

5. MM of H2O = (2x1) +16 = 2 + 16 = 18g/mol

Mass of H2O = 2.3g

Number of mole = Mass /Molar Mass

Number of mole of H20 = 2.3/18 = 0.13mol

6. To get the mole of water in the molecular formula, we will find the ratio of the number of mole of anhydrous salt to water as shown below:

Mole anhydrous : mole of water ie

0.02 : 0.13 = 1 : 7

Therefore, the mole of water in the formula is 7 ie

CaCl2.7H20

3 0

3 years ago