Answer:
A sample that has low pH, will have a [OH⁻] < 1x10⁻⁷
Explanation:
Kw = 1x10⁻¹⁴
[H₃O⁺] = 1x10⁻⁷
[OH⁻] = 1x10⁻⁷
If pH is very low, [H₃O⁺] > 1x10⁻⁷
For example, [H₃O⁺] = 1x10⁻³ M
- log [H₃O⁺] = pH
- log 1x10⁻³ M = pH = 3
[OH⁻] will be < 1x10⁻⁷
For the example we made before
pH = 3
pOH = 14 - pH → 11
10^-pOH = [OH⁻]
10⁻¹¹ = 1x10⁻¹¹
Answer:
2.55×10²⁰ atoms of Mo are contained in 40.6 mg
Explanation:
1 atom of Mo has a mass of 1.59×10⁻²² g
So let's think a rule of three for this question.
Firstly, we convert the mass in mg to g
40.6 mg / 1000 = 0.0406 g
In the mass of 1.59×10⁻²² g, there is 1 atom of Mo
In the mass of 0.0406 g there are (0.0406 / 1.59×10⁻²²) = 2.55×10²⁰ atoms
Answer:
washing dishes only when the dishwasher is full
Explanation: