What mass of CaCO3 is required to react completely with 25ml of 0.75M of HCL.
Molarity = number of moles of solute / Volume of solution (in litres)
0.75 = n / 0.025
This gives n = 0.01875
Now, number of moles is given by the following realtion
number of moles = mass of substance / molar mass of substance
So, the mass of HCl will be
0.01875 = mass of HCl / 36.5
mass of HCl = 0.684g
Now, a balanced chemical equation showing the reaction of HCl and CaCO3is as follows
CaCO3 + 2HCl → CaCl2 + H2O + CO2
According to the above equation, 100g of CaCO3 is required to react completely with 71g of HCl. That is
73g of HCl → 100g of CaCO3
1g of HCl → (100 / 73) g of CaCO3
So, 0.684g would require = (100 / 73) X 0.684 g of CaCO3
= 0.937g of CaCO3
Thus 0.937g of CaCO3 would be required to completely react with 25ml of 0.75M HCl.