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frez [133]
3 years ago
13

Can someone pls help me with this question

Chemistry
1 answer:
artcher [175]3 years ago
5 0

Answer:

The answer to your question is 24.325

Explanation:

Data

Magnesium-24  Abundance = 78.70%

Magnesium-25  Abundance = 10.13%

Magnesium-26  Abundance = 11.17%

Process

1.- Convert the abundance to decimals

Magnesium-24  Abundance = 78.70/100 = 0.787

Magnesium-25  Abundance = 10.13/100 = 0.1013

Magnesium-26  Abundance = 11.17/100 = 0.1117

2.- Write an equation

Average atomic mass = (Atomic mass-1 x Abundance 1) + (Atomic mass 2 x

                                       Abundance-2) + (Atomic mass 3 x Abundance 3)

3.- Substitution

Average atomic mass = (24 x 0.787) + (25 x 0.1013) + (26 x 0.1117)

4.- Simplification

Average atomic mass = 18.888 + 2.533 + 2.904

5.- Result

Average atomic mass = 24.325

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Answer : The partial pressure of helium is, 1.815\times 10^4KPa

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As we are given gases in percent, that means 10 g of oxygen gas, 50 g of helium gas and 40 g of nitrogen gas present in 100 g of mixture.

First we have to calculate the moles of oxygen, helium and nitrogen gas.

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Now we have to calculate the partial pressure of helium.

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p_{He} = partial pressure of helium

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X_{He} = mole fraction of helium

Now put all the given values in this formula, we get

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Unknown:

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Solution:

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     Mass of NaOH  = Number of moles x molar mass;

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