Atomic Structure Question 481
Question: Average atomic mass of magnesium is 24.32 amu. This Mg is composed of 79 mole % of $ ^{24}Mg $ and remaining 21 mole % of $ ^{25}Mg $ and $ ^{26}Mg $ . Calculate the mole % of $ ^{25}Mg $
Options:
A) 10%
B) 20%
C) 22%
D) 11%
Show Answer
Answer:
Correct Answer: D
Solution:
- Idea This problem is based on mole concept. This problem can be solved by considering value of mole % of Mg as. Let mole % of $ ^{26}Mg=x $ $ \frac{(21-x)25+x(26)+79(24)}{100}=24.32 $ $ x=10 $% So, % $ ^{25}Mg=21-10=11 $ %