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3 years ago

What’s the molar mass of Lead-208

1 answer:

7 0

Lead is a basic metal and almost 11 isotopes of Lead are reported. The isotopes with greater natural abundance are as follow;

1) ²⁰⁸Pb with abundance 52.4 %

2) ²⁰⁶Pb with abundance 24.1 %

3) ²⁰⁷Pb with abundance 22.1 %

4) ²⁰⁴Pb with abundance 1.4 %

Molar mass of ²⁰⁸Pb:

Molar mass of any element is the total of number of protons, neutrons and electrons.
As, number of protons in Lead are 82 then in ²⁰⁸Pb isotope number of neutrons are...

# of Neutrons = M.mass - # of protons

# of Neutrons = 208 - 82

# of Neutrons = 126

Result:

Molecular Mass of Lead (²⁰⁸Pb) is 208 amu.

# of Protons in ²⁰⁸Pb = 82

# of Neutrons in ²⁰⁸Pb = 126

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8. What is the heat of reaction when hydrogen and oxygen combine to form water?

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The heat of reaction when hydrogen and oxygen combine to form water is :

Explanation:

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3 years ago

An iron(iii) sulfate hydrate is 18.4% water. What is the formula of the hydrate? What is the name of the hydrate?

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Molar mass for Iron(III)sulfate is 399.88 gram per mol and the molar mass for water is 18.02 gram per mol.

We will calculate the moles of Iron(III)sulfate and water present in the compound on dividing their grams by their molar masses as:

$81.6gFe_2(SO_4)_3(\frac{1mol}{399.88g})$

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= $1.02molH_2O$

Now, the next step is to calculate the mol ratio and for this we divide the moles of each by the least one of them means whose moles are less. Here, the moles of Iron(III)sulfate are less than moles of water. So, we divide the moles of each by 0.204.

$Fe_2(SO_4)_3=\frac{0.204}{0.204}$ = 1

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2 years ago