Test Index

NCERT Class XII Chemistry
Chapter - Solutions
Questions with Solutions

© examsnet.com
Question : 44
Total: 53
Calculate the molarity of each of the following solutions :
(a) 30 g of Co(NO3)2·6H2O in 4.3 L of solution (b) 30 mL of 0.5 M H2SO4 diluted to 500 mL (atomic mass of cobalt = 58.7)
Solution:  
(a)‌Molar‌mass‌of‌Co( NO3 )2.6H2 O =58.7+2(14+48)+6×18
=290.7gmol−1
Number of moles of Co( NO3)2.6H2 O=
Mass
‌Molar‌mass

=
30 g
290.7 g mol−1
=0.103
Volume of solution =4.3 L
Molarity of solution =
Number‌of‌moles‌of‌solute
‌Volume‌of‌solution‌in‌L

=
0.103mole
4.3 L
=0.024M
(b) Given V1=30 mL, M1=0.5,V2=500 mL, M2=?
Using formula, V1M1=V2M2
or, 30×0.5=500×M2
or, M2=0.03
Molarity of solution =0.03M
© examsnet.com
Go to Question:
Prev Question
Next Question