Looking at the following answers, and considering the definition of a biological community I believe the answer is D.
Answer:
B. water displacement is used "graduated cylinder is filled with water (100 mL) and the object is then put inside. ... If the new water level is (120 mL) we now know that the object has a volume of 20 mL."
Explanation:
We need to first add both of the solution volumes together 35+115=150. Now we can divide the volume of the ethanol by the total volume 35/150=.233. To double check we can multiply the total volume by the percentage of ethanol by volume we got as a solution 150x.233=35. So the percentage by volume of ethanol in the solution is .233x100=23.3%.
Solubility is the ability of a substance to dissolve in another substance.
Answer:
Mass = 36.38 g
Explanation:
Given data:
Mass of hydrogen = 30.0 g
Mass of nitrogen = 30.0 g
Theoretical yield of reaction = ?
Mass of ammonia = ?
Chemical equation:
N₂+ 3H₂ → 2NH₃
Number of moles of N₂:
Number of moles = Mass /molar mass
Number of moles = 30 g / 28 g/mol
Number of moles = 1.07 mol
Number of moles of H₂:
Number of moles = Mass /molar mass
Number of moles = 30 g / 2g/mol
Number of moles = 15 mol
Now we will compare the moles of NH₃ with hydrogen and nitrogen .
H₂ : NH₃
3 : 2
15 : 2/3×15= 10 mol
N₂ : NH₃
1 : 2
1.07 : 2 × 1.07= 2.14 mol
The number of moles of NH₃ produced by nitrogen are less it will be limiting reactant.
Mass of ammonia:
Mass of NH₃ = moles × molar mass
Mass =2.14 mol × 17 g/mol
Mass = 36.38 g
