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3 years ago

What is the mass of 2.25 x 10^25 atoms of lead

Chemistry

1 answer:

NemiM [27]3 years ago

5 0

Answer: the amount of a substance that contains 6.02 x 1023 respective particles of that

substance

Avogadro’s number: 6.02 x 1023

Molar Mass: the mass of one mole of an element

CONVERSION FACTORS:

1 mole = 6.02 x 1023 atoms 1 mole = atomic mass (g)

Try:

1. How many atoms are in 6.5 moles of zinc?

6.5 moles 6.02 x 1023 atoms = 3.9 x 1024 atoms

1 mole

2. How many moles of argon are in a sample containing 2.4 x 1024 atoms of argon?

2.4 x 1024 atoms of argon 1 mole = 4.0 mol

6.02 x 1023 atoms

3. How many moles are in 2.5g of lithium?

2.5 grams Li 1 mole = 0.36 mol

6.9 g

4. Find the mass of 4.8moles of iron.

4.8 moles 55.8 g = 267.84 g = 270g

1 mole

MOLE PARTICLES

(ATOM)

MASS

(g)

1 mole = molar

mass

(look it up on

the PT!)

1 mole =

6.02 x 1023

atoms

1 mole = 6.02 x 1023 atoms 1 mole = atomic mass (g)

Two Step Problems:

1. What is the mass of 2.25 x 1025 atoms of lead?

2.25 x 1025 atoms of lead 1 mole 207.2g = 7744.19g = 7740g

6.02 x 1023 atoms 1 mole

2. How many atoms are in 10.0g of gold?

10 g gold 1 mole 6.02 x 1023 atoms = 3.06 x 1022 atoms

197.0g 1 mole

PRACTICE PROBLEMS:

1. How many moles are equal to 625g of copper?

625g of copper 1 mol = 9.77 mol Cu

64 g Cu

2. How many moles of barium are in a sample containing 4.25 x 1026 atoms of barium?

4.25 x 1026 atoms of barium 1 mol = 706 mol

6.02 x 1023 atoms

3. Convert 2.35 moles of carbon to atoms.

2.35 moles 6.02 x 1023 atoms = 1.41 x 1024 atoms

1 mole

4. How many atoms are in 4.0g of potassium?

4.0 g 1 mole 6.02 x 1023 atoms = 6.2 x 1022 atoms

39.1 g 1 mole

1 mole = 6.02 x 1023 atoms 1 mole = atomic mass (g)

5. Convert 9500g of iron to number of atoms in the sample.

9500 g Fe 1 mole 6.02 x 1023 atoms = 1.0 x 1026 atoms

55.8g 1 mole

6. What is the mass of 0.250 moles of aluminum?

0.250 moles 27.0g = 6.75 g Al

1 mole

7. How many grams is equal to 3.48 x 1022 atoms of tin?

3.48 x 1022 atoms 1 mole 118.7g = 6.86 g Sn

6.02 x 1023 atoms 1 mole

8. What is the mass of 4.48 x 1021 atoms of magnesium?

4.48 x 1021 atoms 1 mole 24.3g = 0.181 g Mg or 1.8 x 10-1

6.02 x 1023 atoms 1 mole

9. How many moles is 2.50kg of lead?

2.50kg 1000 g 1 mol = 12.1 mol

1 kg 207.2 g

10.Find the mass, in cg, of 3.25 x 1021 atoms of lithium.

3.25 x 1021 atoms 1 mol 6.9g 100cg = 3.7

Explanation:

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What is the mass of calcium in 2.3•10^23 molecules of calcium phosphate

Katena32 [7]

Explanation:

N(Ca)=3×N(Ca₃(PO₄)₂)=

=3×2.3×10²³=6.9×10²³

6.02×10²³→40g

6.9×10²³→Xg

m(Ca)=X≈45.85g

3 0

3 years ago

For each set of reactions, determine the value of δh2 in terms of δh1. a+b→2c,δh1 1/2a+1/2b→c,δh2=? express your answer in terms

allochka39001 [22]

ΔH2 = - δH1 δH2 = - 2 x δH1 δH2 = 2 x <span>δ</span>H1

3 0

3 years ago

Why is it necessary to obtain 25 to 50 hairs from this woman?

Vedmedyk [2.9K]

To get the correct data

5 0

2 years ago

A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is

Anuta_ua [19.1K]

The maximum safe operating temperature for this reaction is equal to 895°C.

<u>Given the following data:</u>

Width of cylinder = 22 cm.

Height, h = 26.4 cm.

Maximum safe pressure = 6.30mpa.

Mass = 0.537 kg.

<u>Scientific data:</u>

Ideal gas constant, R = 8.314 L-kPa/Kmol.

Molar mass of of dinitrogen monoxide ( $N_2F_2$ ) gas = 66 g/mol.

Radius, r = $\frac{width}{2} =\frac{22}{2} =11\;cm$

<h3>How to calculate the maximum safe operating temperature.</h3>

First of all, we would determine the volume of the stainless-steel cylinder by using this formula:

$V=\pi r^2 h\\\\V = 3.142 \times 11^2 \times 26.4\\\\$

Volume, V = 10,036.81 $cm^3$ .

In liters, we have:

Volume, V = 10.04 Liters.

Next, we would determine the number of moles of dinitrogen monoxide ( $N_2F_2$ ) gas:

$Number \;of \;moles = \frac {mass}{molar\;mass}\\\\Number \;of \;moles = \frac {537}{66}$

Number of moles = 8.136 moles.

Now, we can solve for the maximum safe operating temperature by applying the ideal gas equation:

$PV=nRT\\\\T=\frac{PV}{nR} \\\\T=\frac{6.30 \times 10^3 \times 10.04}{8.136 \times 8.314}\\\\T=\frac{60541.2}{67.6427}$

T = 895.02 ≈ 895°C.

Read more on temperature here: brainly.com/question/24769208

5 0

2 years ago

The reaction H2(g)+F2(g)?2HF(g) is spontaneous at all temperatures. A classmate calculates the entropy change for this reaction

Pachacha [2.7K]

Answer:

The correct answer is there is a mistake in the calculation. The second law of thermodynamics state that in any spontaneous process there is an increase in the entropy of the universe.

Explanation:

According to the second law a reaction will occur in a system spontaneously if the total entropy of both system and surrounding increases during the reaction.That means in case of spontaneous reaction entropy change is always positive.

But according to the question the reaction H2+F2=2HF is spontaneous in all temperature.So according to the second law of thermodynamics i can say that my classmate made a mistake in calculation that"s why his result for entropy change comes negative.

6 0

3 years ago