3) 8. From 392 mg of H2S04. 1,204 x 10 molecules are removed. The mole

1.	3) 8. From 392 mg of H2S04. 1,204 x 10 molecules are removed. The moles of H2S04 left is20 x 10-B) 1.2 x 10-3C) 4.0 x 10-3D) 1.5 x 10-3
Answer» This question applies the concept of Avogadros law. Avogadros constant is as follows : 1 mole of a substance = 6.022 × 10²³ molecules. How many moles are equivalent to 1.2 × 10²¹ molecules We get this by : (1.2 × 10²¹) / (6.022 × 10²³) = 0.001993 molesThe amount of moles in 392mg of H₂SO₄ is : 392 mg = 0.392 g Molar mass of H₂SO₄ = 98g/mol Moles = mass in grams /molar mass = 0.392/98 = 0.004 moles The amount of moles removed = 0.001993moles Remaining moles = 0.004 - 0.001993 = 0.002007 moles

3) 8. From 392 mg of H2S04. 1,204 x 10 molecules are removed. The moles of H2S04 left is20 x 10-B) 1.2 x 10-3C) 4.0 x 10-3D) 1.5 x 10-3

Answer»

This question applies the concept of Avogadros law.

Avogadros constant is as follows :

1 mole of a substance = 6.022 × 10²³ molecules. How many moles are equivalent to 1.2 × 10²¹ molecules

We get this by :

(1.2 × 10²¹) / (6.022 × 10²³) = 0.001993 molesThe amount of moles in 392mg of H₂SO₄ is :

392 mg = 0.392 g

Molar mass of H₂SO₄ = 98g/mol

Moles = mass in grams /molar mass

= 0.392/98 = 0.004 moles

The amount of moles removed = 0.001993moles

Remaining moles = 0.004 - 0.001993 = 0.002007 moles