When PH = ㏒(H^+)
[H+] = 10^-3.67
[H+] = 2.14x 10^-4
so according to the reaction equation:
HF ↔ H^+ + F^-
at equilibrium X-(2.14x10^-4) (2.14x10^-4) (2.14x10^-4)
by substitution in Ka formula:
Ka = [H+][F]-/[HF]
6.8x10^-4 = (2.14x10^-4)*(2.14x10^-4) /(X-2.4x10^-4)
X-2.4x10^-4 = (4.58x10^-8)* (6.8x10^-4)
∴X = 2.4x10^-4
∴[HF] = X- (2.14x10^-4)= (2.4x10^-4)-(2.14x10^-4) = 2.6 X 10^-5
Answer:
Explanation:
An atom on a face is shared by two unit cells, so only half of the atom belongs to each of these cells. An atom on an edge is shared by four unit cells, and an atom on a corner is shared by eight unit cells.
Answer:
Heat energy is transferred to cooler objects to reduce the temperature of those objects.
Explanation:
The fourth option is not correct.
A correct way of writing it would be : " Heat energy is transferred from cooler objects to reduce the temperature of those objects.". When an object loses heat energy, its temperature reduces. Conversely, when an object receives heat energy, its temperature increases.
Answer:
a and B are correct
Explanation:
The energy of an electron associated with one shell around the nucleus is quantized. And is given by the formula
.
where n= shell number 1,2,3...
It is true that energy of an electron cab be measured and Each electron around an atom has a discrete measure of energy associated with it. Moreover, quantity of electron energy remains constant in a shell and changes only when the electron changes its shell.
hence C is incorrect.
Through the erosion and indentations. Formation down cutting it leaves forms of a river or ocean carved. Using range you can see how the floor of the canyon were an ocean floor. Erosion is caused by water the Grand Canyon sits on a body of water unlike most canyons this one happened to erode and sediment the body where the water once was. A layer of rock is also apparent which you wouldn’t be able to see unless erosion happened and etc.