Answer:
D
Explanation:
Firstly in deciding whether the meniscus of a liquid in a glass capillary tube will be convex or concave, we need to understand 2 forces that are in play here. These are the adhesive and cohesive forces.
The cohesive forces are the forces between the molecules present in the liquid. It can be seen as the force of attraction between the molecules of the liquid
The adhesive forces are the forces between the molecules of the liquid and the molecules of the glass.
The reason why mercury has a convex meniscus is because the cohesive forces between the mercury molecules is greater than the adhesive forces between the molecules of the glass and molecules of mercury.
What we are saying in essence is that the intramolecular force of attraction between mercury molecules is greater than the intermolecular force of attraction between the molecules of the glass and water.
Hence we say mercury does not wet glass as the cohesive forces of attraction are greater than the adhesive attraction forces
Urmmm??????? What is the question
Answer
A runner ran 20 miles in 150 minutes. If she runs at that ... run in 15 minutes? How fast is she running in miles per hour? What is her pace in minutes per mile?
Explanation:
Using the ideal gas equation pV = nRT, where R is the ideal gas constant, we can show that p=nRT/V. Since n, R and T are all constants, p2/p1 = V1/V2 where p1 and p2 are the start and final pressures respectively and V1 and V2 are the start and final volumes respectively. For if p1 = 3*p2, the pressure would have fallen to one third of its original value, and it follows that V2 = 3*V1. Therefore, for the pressure to fall to a third of its original value, the volume must increase by a factor of 3.
Answer: 253.8
Explanation:
The molar mass of iodine is 126.904. Multiply that by two and you get approximately 253.8 grams in two moles.
