1.06g of Na2CO3 is dissolved in water to make 250cm^3 solution. 10.0 cm^3 of this solution was further diluted to make 500cm^3 of 2nd solution. 25.0cm^3 of 2nd solution reacted with 28.5cm^3 of HCl. Find the concentration of HCl in mol/dm^3

Na2CO3 + 2HCl ==> 2NaCl + 2H2O + CO2

grams Na2CO3 actually titrated is
1.06 x (10/250) x 2(25/500) = ?
mols Na2CO3 titrated = ?g/molar mass Na2CO3.
mols HCl used = 2*mols Na2CO3

Then M = mols HCl/L HCl = ?

To find the concentration of HCl in mol/dm³, you first need to determine the amount of Na2CO3, which reacts with HCl. Then, you can use stoichiometry to convert the amount of Na2CO3 to HCl. Here's a step-by-step explanation of how to solve this problem:

Step 1: Determine the number of moles of Na2CO3
To find the number of moles of Na2CO3, you'll use the formula:
moles = mass / molar mass

Given that the mass of Na2CO3 is 1.06g and the molar mass of Na2CO3 is 105.99 g/mol, you can calculate the moles of Na2CO3 as follows:
moles = 1.06g / 105.99 g/mol

Step 2: Calculate the concentration of Na2CO3
The concentration is expressed as moles per liter (mol/dm³). You have a 250cm³ (which is equivalent to 0.25dm³) of solution containing the Na2CO3.

To find the concentration of Na2CO3, you can use the formula:
concentration = moles / volume

concentration = moles / 0.25 dm³

Step 3: Dilution calculation
You are given that 10.0 cm³ of the Na2CO3 solution was diluted to make a 500cm³ (which is equivalent to 0.5dm³) of a second solution.

To find the final concentration of Na2CO3, you can use the dilution formula:
C1V1 = C2V2

C1 = initial concentration
V1 = initial volume
C2 = final concentration
V2 = final volume

You can rewrite the formula as:
C2 = (C1 * V1) / V2

Step 4: Determine the moles of HCl
You are given that 25.0cm³ of the second solution reacted with 28.5cm³ of HCl. This reaction tells you that the moles of HCl is the same as the moles of Na2CO3.

Step 5: Calculate the concentration of HCl
Using the moles of HCl and the volume of the HCl solution (which is 25.0cm³), you can calculate its concentration in mol/dm³ using the formula:
concentration = moles / volume

Substitute the moles of HCl and the volume into the formula to get the concentration in mol/dm³.

That's it! Now you know the step-by-step process for finding the concentration of HCl in mol/dm³. Just plug in the given values and perform the necessary calculations to find the final answer.