Solutions Question 413
Question: Concentrated $ HNO_3 $ is 63% $ HNO_3 $ by mass and has a density of 1.4 g/mL. How many millilitres of this solution are required to prepare 250 mL of a 1.20 M $ HNO_3 $ solution'
Options:
A) 18.0
B) 21.42
C) 20.0
D) 14.21
Show Answer
Answer:
Correct Answer: B
Solution:
m-moles of $ HNO_3 $ required $ =250\times 1.2=300 $
100 g solution contain 1 mole $ HNO_3 $
$ \frac{100}{1.4}mL $ solution contain 1 mole $ HNO_3 $
$ CO_2 $ molarity of $ HNO_3 $ solution
$ =\frac{1000}{100}\times 1.40=14 $
$ \therefore $ $ 14\times V=300 $ or $ V=21.42,mL $
