According to the reaction equation:
and by using ICE table:
CN- + H2O ↔ HCN + OH-
initial 0.08 0 0
change -X +X +X
Equ (0.08-X) X X
so from the equilibrium equation, we can get Ka expression
when Ka = [HCN] [OH-]/[CN-]
when Ka = Kw/Kb
= (1 x 10^-14) / (4.9 x 10^-10)
= 2 x 10^-5
So, by substitution:
2 x 10^-5 = X^2 / (0.08 - X)
X= 0.0013
∴ [OH] = X = 0.0013
∴ POH = -㏒[OH]
= -㏒0.0013
= 2.886
∴ PH = 14 - POH
= 14 - 2.886 = 11.11
D. Air molecules touch the warm ground, heating them up
This is a chemical change because there is a new substance that was created and the new chemical can cause other chemical reaction to happen compared to the 1st state of chemical that was in the cave. Because the cave water was exposed to another environment, the calcium bicarbonate, which is also known as salt. When the cave's groundwater was exposed to a different environment the atom in the cave water rearranged and crystallized.
Answer:
These two numbers are fixed for an element. The mass number tells us the number the sum of nucleons of protons and neutrons in the nucleus of an atom. The atomic number also known as the proton number is the number of protons found in the nucleus of an atom. ... The atomic number uniquely identifies a chemical element.
Explanation:
