Calculate the mass of pure NaCl that will yield enough HCl gas to neutralize 25cm3 of 0•5 of KCO3 solution

To calculate the mass of pure NaCl, we need to calculate the moles of HCl gas first. Then, we can use stoichiometry to determine the moles of corresponding NaCl needed.

Step 1: Calculate the moles of HCl gas
We are given the volume of the KCO3 solution, which is 25 cm^3. To find the moles of HCl gas, we need to use the concentration of the KCO3 solution.

The molarity (concentration) of the KCO3 solution is given as 0.5 M (moles per liter).

First, we need to convert the volume from cm^3 to liters:
25 cm^3 = 25 / 1000 = 0.025 liters

Now, we can calculate the moles of HCl gas using the given volume and molarity:
Moles of HCl = Volume (in liters) x Molarity
Moles of HCl = 0.025 L x 0.5 M = 0.0125 moles

Step 2: Determine the moles of NaCl
The balanced chemical equation for the reaction between KCO3 and HCl is:
2KCO3 + 2HCl -> 2KCl + H2O + CO2

From the balanced equation, we can see that the stoichiometric ratio between KCO3 and HCl is 2:2. It means that for every 2 moles of KCO3, 2 moles of HCl will be required.

So, the moles of NaCl will be the same as the moles of KCO3 because 1 mole of NaCl will give rise to 1 mole of KCO3.

Moles of NaCl = Moles of KCO3 = 0.0125 moles

Step 3: Calculate the mass of NaCl
Now that we have the moles of NaCl, we can use the molar mass of NaCl to calculate the mass.

The molar mass of NaCl is 58.44 g/mol (sodium atomic mass = 22.99 g/mol, chlorine atomic mass = 35.45 g/mol).

Mass of NaCl = Moles of NaCl x Molar mass of NaCl
Mass of NaCl = 0.0125 moles x 58.44 g/mol

Therefore, the mass of pure NaCl that will yield enough HCl gas to neutralize 25 cm^3 of 0.5 M KCO3 solution is:
Mass of NaCl = 0.0125 moles x 58.44 g/mol = 0.73 g (rounded to two decimal places)

So, the mass of pure NaCl needed is approximately 0.73 grams.

0.5 what?

KCO3. No such animal.