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4 years ago

Calculate the number of atoms in 52g of He.

Chemistry

1 answer:

MissTica4 years ago

5 0

Answer:

78.3 × 10²³ atoms of helium are present in 52 g.

Explanation:

Given data:

Mass of He = 52 g

Number of atoms = ?

Solution:

First of all we will calculate the number of moles of He

Number of moles = mass /molar mass

Number of moles = 52 g/ 4 g/mol

Number of moles = 13 mol

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

1 mole = 6.022 × 10²³ atoms of helium

13 mol × 6.022 × 10²³ atoms of helium / 1 mole

78.3 × 10²³ atoms of helium

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3 years ago

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Answer:

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Explanation:

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It maybe a bit confusing that we almost have half of our original concentration of AB, and from the first part we know the half-life was 31.3 s.

But, you have to realize that the half-life for second order reactions depend on the initial concentration ( different from first order ). Calculating the half life in this part with an original concentration of 0.240 M gives us a half-life of 75.8 s which makes sense with our result.

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4 years ago

Calculate the number of atoms in 52g of He.​

Calculate the number of atoms in 52g of He.