Answer:
Using the information provided in the question, the percentage by mass of ethanol in the blood is 0.1949%.
Explanation:
The balanced equation for the reaction can be written as:
3CH3CH2OH + 2K2Cr2O7+ 16H+ >>>> 3CH3COOH + 4Cr3+ + 4K+ + 11H2O. This will be used to solve the problem.
The no of moles of K2Cr2O7 used = concentration X volume in dm cube.
= 0.05 X 22.6/1000 = 1.13/1000 = 0.00113 moles of K2Cr2O7 was used.
From the balanced equation above, 3 moles of ethanol will react with 2 moles of K2Cr2O7.
Therefore, 0.00113 X 3/2 moles of ethanol would have been in the blood of the subject = 0.001695 moles of ethanol.
Remember that no of moles = mass/molar mass. Then mass = moles X molar mass.
The molar mass of ethanol is 46g/mole.
Then mass = 0.001695 X 46 = 0.07797gram of Ethanol was in the blood.
Percentage by mass in blood is: 0.07797/40 X 100 = 0.1949%
Answer:
2.83 g
Explanation:
At constant temperature and pressure, Using Avogadro's law
Given ,
V₁ = 2.12 L
V₂ = 3.12 L
n₁ = 0.120 moles
n₂ = ?
Using above equation as:
n₂ = 0.17660 moles
Molar mass of methane gas = 16.05 g/mol
So, Mass = Moles*Molar mass = 0.17660 * 16.05 g = 2.83 g
<u>2.83 g are in the piston.</u>
A student fires a bow and arrow in gym class and all his arrows land close to eachother but not on the bullseye. this student could be said to be:
precise but not accurate
V = 3.00 x 3.00 x 3.00 => 27 cm³
D = m / V
8.90 = m / 27
m = 8.90 x 27
m = 240.3 g
Answer:
no
Explanation:
a cell is something that either stays inside of something or is a individual floating object and it does not compare to bigger sized materials
