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
Answer:
The elements become less reactive.
Explanation:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction and reactivity increases because of greater electron affinity.
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased. The electron affinity decreases because of shielding effect and thus atom become less reactive.
Answer:
no
Explanation:
Small marble chips reacts faster
Note: Above question is incomplete: Complete question is read as
<span>According the the arrhenius theory, which species does an acid produce in an aqueous solution?
</span>A) hydrogen ions B) hydroxyl ions C) Sodium ions D) Chloride ion
.....................................................................................................................
Correct answer for above question is A) Hydrogen ions
Reason:
According the Arrhenius theory of acid and base, acid generates hydrogen ions in aqueous medium, while bases generates hydroxyl ions in aqueous medium.
Example of Acid:
HCl(aq) → H+(aq) + Cl-(aq)
Example of Base:
NaOH(aq) → Na+(aq) + OH-(aq)
Answer:
equal to M
Explanation:
The mass of the fully melted mass and the initial solid will be the same. So, the mass of the melt is equal to M.
Mass is the amount of matter contained within a substance. Since only the phase changed and the amount of matter is still the same, the mass of the molten phase and the solid phase will remain the same.
We are correct to say that in the heating process no mass was destroyed or added in melting the solid.
A simple phase change that preserved the mass only occurred.
