What are the phrases I don’t see any pictures??
Answer:
1) correct
2) incorrect
3) correct
4)incorrect
Explanation:
1) A Lewis acid is a substance that accepts a nonbonding pair of electrons.
A Bronsted-Lowry acid is a substance that donates a proton H⁺
Since the donation of a proton involves the acceptance of a pair of electrons, every Bronsted-Lowry acid is also a Lewis acid.
2)A Lewis acid not necessarily needs to have a proton to be donated.
3) Conjugated acids of weak bases are strong acids and conjugated acids of strong bases are weak acids.
4)K⁺ comes from a strong base, therefore is does not have an acidic behaviour.
Answer:
19) 3.6920 × 10⁻⁵
20) 4.059× 10²
21) 2.46810121416 × 10³
22) 1.0000× 10⁻³
Explanation:
Scientific notation is the way to express the large value in short form.
The number in scientific notation have two parts.
The digits (decimal point will place after first digit)
× 10 ( the power which put the decimal point where it should be)
For example:
0.000036920
In scientific notation = 3.6920 × 10⁻⁵
405.9
In scientific notation = 4.059× 10²
2468.10121416
In scientific notation = 2.46810121416 × 10³
0.0010000
In scientific notation = 1.0000× 10⁻³
First, we need to get the value of Ka:
when Ka = Kw / Kb
we have Kb = 1.8 x 10^-5
and Kw = 3.99 x 10^-16 so, by substitution:
Ka = (3.99 x 10^-16) / (1.8 x 10^-5) = 2.2 x 10^-11
by using the ICE table :
NH4+ + H2O →NH3 + H+
intial 0.013 0 0
change -X +X +X
Equ (0.013-X) X X
when Ka = [NH3][H+] / [NH4+]
by substitution:
2.2 x 10^-11 = X^2 / (0.013 - X) by solving this equation for X
∴X = 5.35 x 10^-7
∴[H+] = X = 5.35 x 10^-7
∴PH = - ㏒[H+]
= -㏒(5.35 x 10^-7)
= 6.27
