Answer:
pH → 7.46
Explanation:
We begin with the autoionization of water. This equilibrium reaction is:
2H₂O ⇄ H₃O⁺ + OH⁻ Kw = 1×10⁻¹⁴ at 25°C
Kw = [H₃O⁺] . [OH⁻]
We do not consider [H₂O] in the expression for the constant.
[H₃O⁺] = [OH⁻] = √1×10⁻¹⁴ → 1×10⁻⁷ M
Kw depends on the temperature
0.12×10⁻¹⁴ = [H₃O⁺] . [OH⁻] → [H₃O⁺] = [OH⁻] at 0°C
√0.12×10⁻¹⁴ = [H₃O⁺] → 3.46×10⁻⁸ M
- log [H₃O⁺] = pH
pH = - log 3.46×10⁻⁸ → 7.46
Answer:
It emits 1.64 x 10⁻¹⁸J of energy
Explanation:
The n = 1 is a lower quantum level compared to n = 2.
When a hydrogen atom moves from a higher level to a lower one, it simply emits the energy difference between the two levels.
- If a hydrogen atom moves from a lower energy level to a higher one such as from 1 to 2, they absorb the energy difference to attain the new excited state.
- So, for an electron in the hydrogen atom to move from a higher energy level to a lower one, it must emit 1.64 x 10⁻¹⁸J of energy.
In order to calculate the average value of cells B2:B6, you need to enter the formula on cell B7, On the Home tab, in the Editing group, click the Sum (AutoSum) button arrow and select Average . (and press Enter). The answer in this question is On the Home tab, in the Editing group, click the Sum (AutoSum) button arrow and select Average . (and press Enter).
Answer:
43.75 ml
Explanation:
Given that the equation of the reaction is;
2HNO3(aq) + Ca(OH)2(aq) ---> Ca(NO3)2(aq) + 2 H20(l)
Concentration of acid CA= 0.05 M
Concentration of base CB = 0.02 M
Volume of acid VA = 35.00ml
Volume of base VB= ???
Number of moles of acid NA= 2
Number of moles of base NB=1
From
CAVA/CBVB= NA/NB
Making VB the subject of the formula;
VB= CAVANB/CBNA
VB= 0.05 × 35 × 1/ 0.02 × 2
VB=1.75 /0.04
VB= 43.75 ml
