Question

chlorophyll the green colouring matter of plants responcible for photosynthesis contains 2.68% of magnesium by mass.calculate the number of magnesium atom in 2.00 g of chlorophyll

Answer 1

Answer:

the ans for the question is 1.3 * 10^21

Answer 2

Answer:

1.345 × 10²¹ atoms of magnesium

Explanation:

Given:

Mass of the chlorophyll = 2.00 g

Mass of the magnesium = 2.68% of the mass of the chlorophyll

= 0.0268 × 2 = 0.0536 g

thus,

moles of magnesium = mass of magnesium / molar mass of the magnesium

moles of magnesium, n = 0.0536 / 24 = 2.233 × 10⁻³ moles

Now,

1 mole of magnesium contains 6.023 x 10²³ atoms of Mg

therefore,

2.233 × 10⁻³ moles of magnesium have

= 6.023 x 10²³ × 2.233 × 10⁻³ atoms of Mg

or

= 1.345 × 10²¹ atoms of magnesium