Some Basic Concepts of Chemistry - Result Question 62

Answer:

Correct Answer: 61. 20%

Solution:

61. Average atomic weight

$\begin{aligned} & =\frac{\Sigma \text { Percentage of an isotope } \times \text { Atomic weight }}{100} \\ \Rightarrow 10.81 & =\frac{10.01 x+11.01(100-x)}{100} \Rightarrow x=20 %\end{aligned}$

Therefore, natural boron contains 20% (10.01) isotope and 80% of the other isotope.

Topic 2 Equivalent Concept, Neutralisation and Redox Titration