Answer:
a) in pure water:
⇒ S (25°C) Ni(OH)2 = 2.0 E-5 M
b) in 0.013 M NaOH:
⇒ S = 9.467 E-11 M
Explanation:
a) Ni(OH)2 ↔ Ni2+ + 2OH-
S S 2S
⇒ Ksp = [ Ni2+ ] * [ OH- ]² = 1.6 E-14.....Ksp value comes from the literature
⇒ Ksp = S * 2S² = 1.6 E-14
⇒ 2S³ = 1.6 E-14
⇒ S = ∛( 1.6 E-14 / 2 )
⇒ S = 2.0 E-5 M
b) NaOH ↔ Na+ + OH-
0.0130 M 0.013 0.013
Ni(OH)2 ↔ Ni2+ + 2OH-
S S 2S + 0.0130
⇒ Ksp = [ Ni2+ ] * [ OH- ]²
⇒ Ksp = S * (2S + 0.0130 )² = 1.6 E-14
Due to the small value of the Ksp it can be assumed that "s" is a very small number, so "2s" can be neglected when added to 0.0130.
⇒ 1.6 E-14 = S * ( 0.0130 )²
⇒ S = 9.467 E-11 M
How do the number of electrons in the second energy shell of an atom change going across period 2 in the periodic table?
The answer is: A. The number of electrons increases by 1, from left to right.
B is wrong because atoms in period 2 DO have a second energy shell. For C, the number of electrons in the second energy shell is NOT full. For D, it is wrong to state that the number of electrons increases by 1, from right to left.
Answer:
See explanation
Explanation:
Now , we have the equation of the reaction as;
2H2S(g) + 302(g)------->2SO2(g) + 2H2O(g)
This equation shows that SO2 gas is produced in the process. Let us recall that this same SO2 gas is the anhydride of H2SO4. This means that it can dissolve in water to form H2SO4
So, when SO2 dissolve in rain droplets, then H2SO4 is formed thereby lowering the pH of rain water. This is acid rain.
Answer:
= 200 mL
Explanation:
Using the dilution formula;
M1V1 = M2V2 ;
Where, M1 is the concentration before dilution, V2 is the volume before dilution, while M2 is the concentration after dilution and V2 is the volume after dilution.
M1 = 2.0 M
V1 = 50 mL
M2 = 0.50 M
V2 = ?
V2 = M1V1/M2
= ( 2.0 × 50 )/ 0.5
= 200 mL
Therefore, the volume after dilution will be, 200 mL
Answer: The electron configuration of carbon atom is written as 1s²,2s², 2p².
Explanation:
The electronic configuration of an atom is defined as the arrangement of electrons into the shells or orbit of an atom. The constituents of an atom are proton, neutron and electron. the nucleus of an atom, where most of its mass are concentrated, consists of neutrons and protons fused together. Electrons occupy the shells surrounding the nucleus. The shells are lettered K, L, M, N and so on. Numerically, K shell is numbered 1, L is 2 and so on. These numbers also correspond with the increase in the energy level. All the electrons in K shell for instance belong to the first energy level and they have equal energy.
There is a limit to the number of electrons that can be found in a shell. This can be obtained by a formula 2n² where "n" is the energy level number of the shell.
K: 2n² = 2 × 1² = 2
L: 2n² = 2× 2² = 8
These shells are further subdivided into subshells. There are 4 subshells, s, p, d, and f. Each subshell can hold a different number of electrons.
This electron configuration of carbon can be written as 1s² 2s² 2p² where 1s, 2s, and 2p are the occupied subshells, and the superscript "2" is the number of electrons in each of these subshells.
= 37 amu
= 38 amu
= 39 amu
= 40 amu