Answer:
1.88 g
Step-by-step explanation:
Considering:-
![\%\ of\ the\ citral=(Volume_(citral))/(Volume_(Sample))* 100](https://img.qammunity.org/2020/formulas/chemistry/college/l3czfufrzarekk24cf3z52scy3a5f1epa5.png)
Given that:-
% Citral = 5.72 %
Volume of the citral = 0.120 mL
So,
![5.72=(0.120\ mL)/(Volume_(Sample))* 100](https://img.qammunity.org/2020/formulas/chemistry/college/3kyxqf346nyoozjhyog87l71p3i1ociap3.png)
![Volume_(Sample)=(0.120* 100)/(5.72)\ mL](https://img.qammunity.org/2020/formulas/chemistry/college/u7wyj0yvtyuw4r0mdp9gy9bizw4vtfev82.png)
Volume of the grass oil sample = 2.10 mL
Also, Density of the lemon grass oil = 0.893 g/mL
Mass = Density*Volume = 0.893 g/mL*2.10 mL = 1.88 g
1.88 g of lemon grass oil did you begin with if citral comprises 5.72% of the oil.