Answer:
1. [OH⁻] = 0.30 M ; 2. [OH⁻] = 1.54x10⁻⁶M ; 3. [OH⁻] = 1.32x10⁻¹³M
Explanation:
Remember the rule:
pH + pOH = 14
pOH = 14 - pH
10*⁻pOH (you have to elevate 10, to -pOH)
10*⁻pOH = [OH⁻]
1. 14 - 13.48 = 0.52
10⁻⁰°⁵² = 0.30
2. 14 - 8.19 = 5.81
10⁻⁵°⁸¹ = 1.54x10⁻⁶
3. 14 - 2.12 = 12.88
10⁻¹²°⁸⁸ = 1.32x10⁻¹³
a)
→ 
b)
→ 
<h3>
What are half-reactions?</h3>
The half-reaction method is a way to balance redox reactions. It involves breaking the overall equation down into an oxidation part and a reduction part.
a)
→ 

= 
= -0.83 - (-2.71) =1.88V
b)
→ 
= 
=-0. - (0.8) =-0.8V
Learn more about the half-reactions here:
https://brainly.in/question/18053421
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Answer:
2.0 atoms of K and 1.0 atom of S are needed to form a molecule of potassium sulfide.
Explanation:
- The potassium sulfide has the chemical formula <em>K₂S.</em>
∴ Every 1.0 molecule of K₂S composed of 2.0 atom of K and 1.0 atoms of S.
<u><em>So, 2.0 atoms of K and 1.0 atom of S are needed to form a molecule of potassium sulfide.</em></u>
Answer:
When a number is written in scientific notation, the exponent tells you if the term is a large or a small number. A positive exponent indicates a large number and a negative exponent indicates a small number that is between 0 and 1.