Question

calculate the number of moles in 20 gm of magnesium sulphate
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Answer 1

Answer:1/6

Explanation:

no of moles(n)= Given mass in gm/molar mass

Here given mass=20gm

Molar mass of MgSo4 = molar mass of Mg+S+4×O2 =24+32+4×16= 120

n= 20/120 = 1/6 mole

Hope this will help u...

Answer 2

Given :

• Mass = 20 g
• Magnesium Sulphate (MgSo₄)

To find :

• Number of moles

According to the question,

At first we will find the molar mass of MgSO₄

⇢ Atomic Mass of Magnesium (Mg) = 24 u

⇢ Atomic Mass of Sulphur (S) = 32 u

⇢ Atomic Mass of Oxygen (O) = 16 u

Now we calculate the molecular mass Magnesium Sulphate,

⇢ 24 + 32 + 16 × 4

⇢ 120 u

We know,

⇢ Number of moles = Given mass ÷ Molar mass

⇢ Number of moles = 20 ÷ 120

⇢ Number of moles = 0.167

So,the number of moles is 0.167.

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More details :-

Mole of Atoms :

1 mole of atoms of an element has a mass equal to the gram atomic mass of the element.

Mole of Molecules :

1 mole of molecules of a substance has a mass equal to the gram molecular mass of the substance.

Gram Atomic Mass :

The amount of a substance whose mass in gram is numerically equal to its atomic mass is called gram atomic mass of that substance.

Gram Molecular Mass :

The amount of a substance whose mass in gram is numerically equal to its molecular mass is called gram molecular mass of that substance.