CHEMISTRY MIDDLE SCHOOL

How many atoms are in 26.8 g Fe

Answers

Answer 1

Answer:

2.881x10^23 atoms

Explanation:

From the studies of Avogadro's hypothesis, we discovered that 1mole of any substance contains 6.02x10^23 atoms.

Therefore 1mole of Fe contains 6.02x10^23 atoms.

Molar Mass of Fe = 56g/mol

56g of Fe contains 6.02x10^23 atoms.

Therefore, 26.8g of Fe will contain = (26.8x6.02x10^23) / 56 = 2.881x10^23 atoms

Related Questions

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Why earths atmosphere is like the glass in a greenhouse
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How do machines transfer and convert energy

A 4 kg rock is rolling 10 m/s find its kinetic energy

Answers

The answer is 200 J

The kinetic energy (KE) is:
KE = 1/2 m * v²
m - mass of the object
v - velocity of the object

We have:
m = 4 kg
v = 10 m/s

KE = 1/2 * 4 kg * 10² m/s
KE = 200 J

When it is spring in China, it is ______ in South America

Answers

I would say fall/ autumn in South America because they are in opposite hemispheres.

Please help me!!!30 ptsShow all work and box in your answers.
1. A 15.0 gram sample of a compound is found to contain 8.83 grams of sodium and 6.17 grams of
sulfur. Calculate the empirical formula of this compound.

2. Analysis of a 10.150 gram sample of a compound known to contain only phosphorus and oxygen
indicates a phosphorus content of 4.433 grams. What is the empirical formula of this compound?

3. A compound is found to contain 36.48%Na, 25.41% S, and 38.11% O. Find its empirical formula.

4. A compound is found to contain 63.52% iron and 36.48% sulfur. Find its empirical formula.

5. Qualitative analysis shows that a compound contains 32.38%sodium, 22.65% sulfur and 44.99 %
oxygen. Find the empirical formula of this compound.

6. Analysis of a 20.0 gram sample of a compound containing only calcium and bromine indicates that
4.00 grams of calcium are present. What is the empirical formula of the compound formed?

7. A 60.00 gram sample of tetraethyl lead, a gasoline additive, is found to contain 38.43grams of
lead, 17.83 grams of carbon, and 3.74 grams of hydrogen. Find its empirical formula.

8. Determine the molecular formula for the compound with empirical formula P2O5 and molar mass of
284 g/mol.

9. Determine the molecular formula for the compound with empirical formula OCNCl and molar mass
of 232.41 g/mol.

10. A compound is found to be 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen. Its molar mass is
60.0 g/mol. What is its molecular formula?

11. A compound is 64.9%carbon, 13.5% hydrogen and 21.6% oxygen. Its molar mass is 74.0 g/mol.
What is its molecular formula?

12. A compound is 54.5% carbon, 9.1% hydrogen and 36.4% oxygen. Its molar mass is 88.0 g/mol.
What is its molecular formula?

Answers

Answer:

Question 7 to 12 are given in attached file because character limit is only 5000

Explanation:

1. A 15.0 gram sample of a compound is found to contain 8.83 grams of sodium and 6.17 grams of sulfur. Calculate the empirical formula of this compound.

Given data:

Mass of sample = 15 g

Mass of sodium = 8.83 g

Mass of sulfur = 6.17 g

Empirical formula = ?

Solution:

Number of gram atoms of Na = 8.83 / 23 = 0.4

Number of gram atoms of S = 6.17 / 32 = 0.2

Atomic ratio:

Na : S

0.4/0.2 : 0.2/0.2

2 : 1

Na : S = 2 : 1

Empirical formula is Na₂S.

2. Analysis of a 10.150 gram sample of a compound known to contain only phosphorus and oxygen indicates a phosphorus content of 4.433 grams. What is the empirical formula of this compound?

Given data:

Mass of phosphorus = 4.433 g

Mass of oxygen = 10.150 g - 4.433 g = 5.717 g

Empirical formula = ?

Solution:

Number of gram atoms of P = 4.433 / 30.9738 = 0.1431

Number of gram atoms of O = 5.717/ 15.999 = 0.3573

Atomic ratio:

P : O

0.1431/0.1431 : 0.3573/0.1431

1 : 2.5

P : O = 2(1 : 2.5)

Empirical formula is P₂O₅.

3. A compound is found to contain 36.48%Na, 25.41% S, and 38.11% O. Find its empirical formula.

Given data:

Percentage of sodium = 36.48%

Percentage of sulfur = 25.41%

Percentage of oxygen = 38.11%

Empirical formula = ?

Solution:

Number of gram atoms of Na = 36.48 / 23 = 1.6

Number of gram atoms of S = 25.41/ 32 = 0.8

Number of gram atoms of O = 38.11/ 16 = 2.4

Atomic ratio:

Na : S : O

1.6/0.8 : 0.8/0.8 : 2.4/0.8

2 : 1 : 3

Na: S : O = 2 : 1 : 3

Empirical formula is Na₂SO₃.

4. A compound is found to contain 63.52% iron and 36.48% sulfur. Find its empirical formula.

Given data:

Percentage of iron = 63.52%

Percentage of sulfur = 36.48%

Empirical formula = ?

Solution:

Number of gram atoms of Fe = 63.52 / 55.845 = 1.14

Number of gram atoms of S = 36.48 / 32 = 1.14

Atomic ratio:

Fe : S

1.14/1.14 : 1.14/1.14

1 : 1

Fe : S = 1 : 1

Empirical formula is FeS.

5. Qualitative analysis shows that a compound contains 32.38%sodium, 22.65% sulfur and 44.99 % oxygen. Find the empirical formula of this compound.

Given data:

Percentage of sodium = 32.38%

Percentage of sulfur = 22.65%

Percentage of oxygen = 44.99%

Empirical formula = ?

Solution:

Number of gram atoms of Na = 32.38 / 23 = 1.4

Number of gram atoms of S = 22.65/ 32 = 0.7

Number of gram atoms of O = 44.99/ 16 = 2.8

Atomic ratio:

Na : S : O

1.4/0.7 : 0.7/0.7 : 2.8/0.7

2 : 1 : 4

Na: S : O = 2 : 1 : 4

Empirical formula is Na₂SO₄.

6. Analysis of a 20.0 gram sample of a compound containing only calcium and bromine indicates that 4.00 grams of calcium are present. What is the empirical formula of the compound formed?

Given data:

Mass of sample = 20g

Mass of bromine = 20 g - 4 g = 16 g

Mass of calcium = 4 g

Empirical formula = ?

Solution:

Number of gram atoms of bromine = 16 / 80= 0.2

Number of gram atoms of calcium = 4/ 40= 0.1

Atomic ratio:

Ca : Br

0.1/0.1 : 0.2/0.1

1 : 2

Ca: Br = 1 : 2

Empirical formula is CaBr₂.

Answer:

1)Na2S

2)P2O5

3)Na2SO3

4)FeS

5)Na2SO4

6)CaBr2

7)C8H20Pb

8)P4O10

9)C3Cl3N3O3

10)C2H4O2

11)C4H10O

12)C4H8O2

Explanation:

1. A 15.0 gram sample of a compound is found to contain 8.83 grams of sodium and 6.17 grams of sulfur. Calculate the empirical formula of this compound.

Moles Na = 8.83 grams / 22.98 g/mol = 0.384 moles

Moles S = 6.17 grams / 32.065 g/mol = 0.192 moles

To find the mol ratio we divide by the smallest amount of moles

Na: 0.384 / 0.192 = 2

S: 0.192 /0.192 = 1

For each mol S we have 2 mol Na

The empirical formula is Na2S

2. Analysis of a 10.150 gram sample of a compound known to contain only phosphorus and oxygen indicates a phosphorus content of 4.433 grams. What is the empirical formula of this compound?

Mass of oxygen = 10.150 - 4.433 = 5.717 grams

Moles P = 4.433 grams / 30.97 g/mol

Moles P = 0.143 moles

Moles O = 5.717 grams / 16.0 g/mol = 0.357 moles

To find the mol ratio we divide by the smallest amount of moles

P: 0.143 moles / 0.143 moles = 1

O = 0. 357 moles / 0.143 moles = 2.5

For each P atom we have 2.5 O atoms

The empirical formula is P2O5

3. A compound is found to contain 36.48%Na, 25.41% S, and 38.11% O. Find its empirical formula.

Suppose the mass of the compound = 100 grams

Moles Na = 36.48 grams / 22.98 g/mol = 1.587 moles

Moles S = 25.41 grams / 32.065 g/mol = 0.792 moles

Moles O = 38.11 grams / 16.0 g/mol = 2.382 moles

To find the mol ratio we divide by the smallest amount of moles

Na: 1.587 moles / 0.792 moles = 2

S: 0.792 moles / 0.792 moles = 1

O: 2.382 moles / 0.792 = 3

The empirical formula = Na2SO3

4. A compound is found to contain 63.52% iron and 36.48% sulfur. Find its empirical formula.

Suppose the mass of the compound = 100 grams

Moles Fe = 63.52 grams / 55.845 g/mol = 1.137 moles

Moles S = 36.48 grams / 32.065 g/mol = 1.137 moles

The empirical formula is FeS

Chao is thinking about doing a project on plate tectonics for the school science fair. Which design would best relate to how the movement in the Earth’s mantle is related to plate motion?a pot of boiling water to which Chao will add food coloring to show the movement of the water
a flat shallow pan filled with a thick liquid heated by a hot plate with thick wooden blocks on top of the liquid
a flat shallow pan filled with small metal beads topped by an assembled puzzle that is shaken from side to side
a flat shallow pan filled with a thick liquid that can be heated by a hot plate with pieces of a thin plastic sheet floating on top of the liquid

Answers

The correct answer is option D) a flat shallow pan filled with a thick liquid that can be heated by a hot plate with pieces of a thin plastic sheet floating on top of the liquid.

I just did the quiz and got it right!

Hope this helps and have a gr8 day buddies <3

Answer:

Explanation:

Explain how a gene pool and biological evolution are related

Answers

The ones that are able to survive pass on their genes to the next generation. Bye doing that they pass on certain traits to the next generation causing them to inherit those traits and develop new ones and that prosses repeats for thousands and millions of years and that's how they are able to evolve.

Titanium has three common isotopes: 46Ti (8.0%) , 48Ti (73.4%) , 49Ti 5.5%, 50Ti ( 5.3%). What is the average atomic mass of titanium? Work please too!

Answers

you can use its mass number, A , as an approximation of its atomic mass.
In this case, you will have
46
Ti → ma ≈ 46 u

47
Ti →ma≈47 u

48
Ti →ma≈48 u

49
Ti →ma≈49 u

50
Ti →ma≈50 u
Now, the average atomic mass of titanium is calculated by taking the weighted average of the atomic masses of its stable isotopes.
Simply put, each isotope
i
will contribute to the average atomic mass of the element in proportion to its decimal abundance, which is simply the percent abundance divided by
100

The decimal abundances for these five isotopes will be
46
Ti:
8.0/100= 0.080
47
Ti: 7.8/100=0.078

48
Ti: 73.4/100 =0.734
49
Ti: 5.5/100=0.055
50
Ti: 5.3/100=0.053
The average atomic mass of titanium will thus be avg. atomic mass =46 u ×0.080+47 u ×0.078
+48 u ×0.734+49 u × 0.055 + 50 u × 0.053
avg. atomic mass
= 47.923 u

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