JEE Main 2020 — Redox Reactions Question with Solution
From: JEE Main 2020 (Online) 4th September Evening Slot
Question
A 100 mL solution was made by adding 1.43 g
of Na2CO3.xH2O. The normality of the solution
is 0.1 N. The value of x is _____.
(The atomic mass of Na is 23 g/mol)
(The atomic mass of Na is 23 g/mol)
Enter your answer
Show full solutionCorrect answer: 10
Correct answer
10
Step-by-step explanation
Molar mass of Na2CO3.xH2O
= 23 × 2 + 12 + 48 + 18x
= 46 + 12 + 48 + 18x
= (106 + 18x)
As nfactor in dissolution will be determined from net cationic or anionic charge; which is 2
Eq wt = = (53 + 9x)
volume = 100 ml = 0.1 Litre
Normality =
0.1=
53 + 9x = 143
9x = 90
x = 10
= 23 × 2 + 12 + 48 + 18x
= 46 + 12 + 48 + 18x
= (106 + 18x)
As nfactor in dissolution will be determined from net cationic or anionic charge; which is 2
Eq wt = = (53 + 9x)
volume = 100 ml = 0.1 Litre
Normality =
No. of equivalents of solute
Volume of solution (in L)
0.1=
53 + 9x = 143
9x = 90
x = 10
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