Given :
Mass of caffeine at dangerous level , m = 3 g .
Coffee contains , 21.5 mg/oz OF caffeine .
Mass of cup , 8 oz/cup .
To Find :
Number of cups till dangerous level .
Solution :
Caffeine in a cup of coffee is given by :
Now , number of cups at the dangerous level is given by :
Now , number of cups should be integer .
Therefore , 18 cups of coffee per day is dangerous .
1 mole of any substance is: 6.022*10²³ atoms or molecules.
9 moles of H₂S=9(6.022*10²³ molecules)=5.4198*10²⁴ molecules.
answer:there are 5.4198*10²⁴ molecules in 9.00 moles of H₂S.
Most fertilizers are rich in nitrogen and phosphorous because they have to replenish nitrogen and phosphorous in the soil, which are essential for plant growth. If they didn't have this, the soil would have to wait fro another cycle and this would hinder plant growth. The correct answer is C.