Answer:
2.88 x 10⁻¹³mol
Explanation:
Given parameters:
Concentration of chlorophyll in seawater = 1.2nanomoldm⁻³
Volume of seawater = 1cm³
Unknown:
Mass of magnesium present = ?
Solution:
To solve this problem, we need to obtain the number of moles of the solute in the sea water.
Since we have been given the value of concentration, our work is easy to do;
Number of moles = concentration x volume
Let us convert the given volume to dm³;
1000cm³ = 1dm³
1cm³ is [tex]\frac{1}{1000}[/tex] = 0.001dm³
Number of moles = 1.2nanomoldm⁻³ x 0.001dm³
= 1.2 x 10⁻³ nanomol
= 1.2 x 10⁻³ x 10⁻⁹mol
= 1.2 x 10⁻¹²mol
Formula of the compound:
C₅₅ H₇₇ Mg N₄ O₅
1 mole of C₅₅ H₇₇ Mg N₄ O₅ contains 1 mole of Mg
1.2 x 10⁻¹²mol of C₅₅ H₇₇ Mg N₄ O₅ will contain 1.2 x 10⁻¹²mol of Mg
Since we now know the number of moles of Mg;
Mass = number of moles x molar mass
= 1.2 x 10⁻¹² x 24
= 28.8 x 10⁻¹²mol
= 2.88 x 10⁻¹³mol
