The first one is the second one and the second one is the first one
Answer:
Explanation:
Freezing water can break rock without any change in the minerals that form the rock (physical weathering). This usually produces small particles and sand. Water with dissolved gases and other chemicals causes the minerals in rocks to be changed, leading to the deterioration of the rock (chemical weathering).
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%
