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3 years ago

If a sample contains 100.0 g of lead atoms (Pb), how many atoms are present in the sample?

Chemistry

2 answers:

Igoryamba3 years ago

7 0

Answer:

The answer to your question is the letter C. 2.906 x 10²³ atoms

Explanation:

Data

mass of Lead = 100 g

The Number of atoms = ?

Process

1.- Look for the atomic number of Lead in the periodic table

Atomic number = 207.2 g

2.- Use proportions and the Avogadro's number to calculate the number of atoms.

207.2 g ------------------ 6.023 x 10²³ atoms

100 g ----------------- x

x = (100 x 6.023 x 10²³) / 207.2

x = 6.025 x 10²⁵ / 207.2

x = 2.906 x 10²³ atoms

bagirrra123 [75]3 years ago

7 0

Answer:

We have 2.906 * 10^23 lead atoms in the sample ( Option C is correct)

Explanation:

Step 1: Data given

Mass of lead atoms = 100.0 grams

Number of Avogadro = 6.022 * 10^23 molecules / mol

Atomic mass of lead = 207.2 g/mol

Step 2: Calcumate moles lead atoms

Moles = mass / molar mass

Moles lead atoms = 100.0 grams / 207.2 g/mol

Moles lead atoms = 0.483 moles

Step 3: Calculate atoms

Number of atoms = number of moles * number of Avogadro

Number of moles = 0.483 moles * 6.022 * 10^23 atoms / mol

Number of moles = 2.906 * 10^23 atoms

We have 2.906 * 10^23 lead atoms in the sample ( Option C is correct)

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3 years ago

1. How many ATOMS of boron are present in 2.20 moles of boron trifluoride ? atoms of boron.

maks197457 [2]

Answer:

1. How many ATOMS of boron are present in 2.20 moles of boron trifluoride? atoms of boron.

2. How many MOLES of fluorine are present in of boron trifluoride? moles of fluorine.

Explanation:

The molecular formula of boron trifluoride is $BF_3$ .

So, one mole of boron trifluoride has one mole of boron atoms.

1. The number of boron atoms in 2.20 moles of boron trifluoride is 2.20 moles.

The number of atoms in 2.20 moles of boron is:

One mole of boron has ---- $6.023x10^2^3$ atoms.

Then, 2.20 moles of boron has

- $=2.20 mol. x 6.023 x 10^2^3 atoms /1 mol\\=13.25x10^2^3 atoms$

2. Calculate the number of moles of BF3 in 5.35*1022 molecules.

$(5.35x10^2^2 molecules/6.023x10^2^3)x 1mol\\=0.0888mol$

One mole of boron trifluoride has three moles of fluorine atoms.

Hence, 0.0888moles of BF3 has 3x0.0888mol of fluorine atoms.

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2 years ago

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Answer:

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Explanation:

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3 years ago

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Answer:

True

Explanation:

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3 years ago

A student analyzed an antacid tablet from a bottle containing 120 tablets purchased for $2.79. The mass of the tablet was 1.247

BaLLatris [955]

The cost of one antacid is 2.325 cents per tablet.

Explanation:

As per the question based on the student analysis we know that,

Total antacid tablets in a bottle = 120

Purchase Price of a bottle = $ 2.79

Cost of 1 antacid tablet $=\frac{2.79}{120}$

As we know $1 = 100 cent

The cost of 1 antacid tablet = $\frac{2.79}{120}$ × 100 cents = 2.325 cents/tablet .

Thus we came to know that it costs 2.325 cents/tablet .

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