AP EAPCET 18 May 2024 Shift 1 Solved Paper

To determine the concentration of a CaCO3 solution in molarity ( mol∕L ), given its concentration is 1000 ppm , we proceed as follows:
Mass of CaCO3 in 1 Liter:
Since 1000 ppm means 1000 mg of CaCO3 per liter, it converts to grams as:
‌

1000×1000mg

1000000

=1g
Calculation of Moles:
The molar mass of CaCO3 is calculated using the atomic masses:
Ca=40‌ u ‌,C=12‌ u, ‌O=16‌ u. ‌
Therefore, the molar mass of CaCO3=40+12+(16×3)=100g∕mol.
Now, calculate the number of moles ( n ):
n=‌

‌ Mass of ‌‌‌CaCO3

‌ Molar mass ‌

=‌

1

100

=0.01mol
Determine Molarity:
The molarity (concentration in mol∕L ) is given by:
‌ Molarity ‌=‌

‌ Number of moles ‌

‌ Volume of solution in ‌L

=‌

0.01

1

=0.01mol∕L=10−2mol∕L
Thus, the concentration of the CaCO3 solution is 10−2mol∕L.