<u>Answer:</u>
(A)
Density = Mass / Volume
So
Mass = Density × Volume
Mole ratio of toluene : Oxygen is 1 : 9
(B)
1 mole of Toluene produces 7 moles of 
gas and 4 moles of 
Vapour
So the mole ratio is 1 : 11
(C)
1mole contains 
molecules
Answer:
Cs is cesium and CrO₄ is chromate so CsCrO₄ is cesium chromate.
Organisms are living things. Us humans are also living things, so we are helpful and harmful to other organisms. For example: we can help another human being with something, or we can help a plant/tree grow if we water it. In return, they also help us by providing us with oxygen. however, we can also be harmful to each other and the environment, for example: we can't hurt each other, or plant or animals by killing them or we can hurt insects by stepping on them. Therefore, organisms are helpful and harmful to each other.
Answer:
Mass of chemical = 1.5 mg
Explanation:
Step 1: First calculate the concentration of the stock solution required to make the final solution.
Using C1V1 = C2V2
C1 = concentration of the stock solution; V1 = volume of stock solution; C2 = concentration of final solution; V2 = volume of final solution
C1 = C2V2/V1
C1 = (6 * 25)/ 0.1
C1 = 1500 ng/μL = 1.5 μg/μL
Step 2: Mass of chemical added:
Mass of sample = concentration * volume
Concentration of stock = 1.5 μg/μL; volume of stock = 10 mL = 10^6 μL
Mass of stock = 1.5 μg/μL * 10^6 μL = 1.5 * 10^6 μg = 1.5 mg
Therefore, mass of sample = 1.5 mg
