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2 years ago

Write the electron configuration for the elements whose atomic numbers are the following:

Chemistry

1 answer:

andreev551 [17]2 years ago

6 0

Answer:

3= Lithium (Li) = [He] 2s1

6= Carbon (C) = [He] 2s2 2p2

8=Oxygen (O)= [He] 2s2 2p4

13=Aluminium (Al)= [Ne] 3s2 3p1

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How many moles in 250g of CBr 4

EleoNora [17]

Answer:

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Explanation: fregrgsrg5

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3 years ago

I’ll give brainliest please help thanks.

oksano4ka [1.4K]

Answer:

See Explanation

Explanation:

The equation of the reaction is;

C7H16(g) + 11O2(g) ---->7CO2(g) + 8H2O(g)

1a) Number of moles in 228 g of H2O = 228 g/18 g/mol = 12.67 moles

From the reaction equation;

11 moles of O2 yields 8 moles of H2O

x moles of O2 yields 12.67 moles of H2O

x = 11 * 12.67/8

x = 17.4 moles of O2

Since 1 mole of O2 occupies 22.4 L

17.4 moles of O2 occupies 17.4 moles * 22.4 L/1 mole = 389.76 L

1b) Molar mass of C7H16 = 100 g/mol

Number of moles in 300 g of C7H16 = 300 g/100g/mol = 3 moles

1 mole of C7H16 yields 7 moles of CO2

3 moles of C7H16 yields 3 * 7/1 = 21 moles of CO2

If 1 mole of CO2 occupies 22.4 L

21 moles of CO2 occupies 21 moles * 22.4 L/1 mole = 470.4 L of CO2

2) Number of moles in 202 L of H2 is obtained by;

1 mole of H2 occupies 22.4 L

x moles of H2 occupies 202 L

x = 1 mole * 202 L/22.4 L = 9 moles of H2

From the reaction equation;

3 moles of H2 yields 2 moles of PH3

9 moles of H2 will yield 9 * 2/3 = 6 moles of PH3

Mass of 6 moles of PH3 = 6 moles of PH3 * 34 g/mol = 204 g of PH3

3 0

3 years ago

You are asked to go into the lab and prepare an acetic acid - sodium acetate buffer solution with a ph of 4.00  0.02. what mola

Oxana [17]

Hello!

To solve this problem we are going to use the Henderson-Hasselbach equation and clear for the molar ratio. Keep in mind that we need the value for Acetic Acid's pKa, which can be found in tables and is 4,76:

$pH=pKa + log ( \frac{[CH_3COONa]}{[CH_3COOH]} )$

$\frac{[CH_3COOH]}{[CH_3COONa}= 10^{(pH-pKa)^{-1}}=10^{(4-4,76)^{-1}}=5,75$

So, the mole ratio of CH₃COOH to CH₃COONa is 5,75

Have a nice day!

5 0

3 years ago

How many moles are in a sample of 4.55 x 10^24 molecules of C3H8?

mestny [16]

Answer: 7.56 moles

Explanation:

C3H8 is the chemical formula for propane, the third member of the alkane family.

Recall that based on Avogadro's number, 1 mole of any substance has 6.02 x 10^23 atoms

So 1 mole of C3H8 = 6.02 x 10^23 atoms

Z moles of C3H8 = 4.55 x 10^24 atoms

To get the value of Z, we cross multiply:

1 x 4.55 x 10^24 atoms = Z moles x (6.02 x 10^23 atoms)

4.55 x 10^24 atoms = Z moles x (6.02 x 10^23 atoms)

To get the value of Z divide both sides by 6.02 x 10^23 atoms

Z moles =4.55 x 10^24 atoms ➗ 6.02 x 10*23 atoms

Hence, Z = 7.56 moles

Thus, the number of propane, C3H8 is 7.56 moles

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3 years ago

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otez555 [7]

I am 90 percent positive that the answer is the first option "Its results are inconsistent over experiments"

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3 years ago