Answer:
4.23.
Explanation:
<em>∵ pH = - log[H⁺].</em>
<em>For weak acids:</em>
∵ [H⁺] = √(ka)(c).
∴ [H⁺] = √(3.5 × 10⁻⁸)(0.10 M) = 5.92 x 10⁻⁵.
∴ pH = - log[H⁺] = - log(5.92 x 10⁻⁵) = 4.2279 ≅ 4.23.
<h3>
Answer:</h3>
D. Allotrope
<h3>
Explanation:</h3>
What is allotropy?
- Allotropy refers to the existence of an element in more than one physical forms.
- Allotropes are therefore different forms of an element with different physical properties or chemical arrangements.
What are some examples of allotropes?
- Examples of elements that exhibit allotropy include, sulfur and carbon.
- Allotropes of carbon are diamond and graphite.
- Allotropes of sulfur are monoclinic sulfur and rhombic sulfur.
Answer:
c. 2 and 3
Explanation:
Ca(NO3)2 names calcium nitrate.
Ca metal, O, N - nonmetals, so Ca(NO3)2 is ionic compound.
It is solid and white.
