how many millimoles of 0.1N H2SO4 will be required for complete reaction with a solution containing 0.125g Na2CO3

To determine how many millimoles of 0.1N H2SO4 are needed to completely react with a solution containing 0.125g of Na2CO3, we first need to understand the chemical reaction involved and how to calculate the equivalents of the reactants.

Understanding the Reaction

Sodium carbonate (Na2CO3) reacts with sulfuric acid (H2SO4) in a neutralization reaction. The balanced chemical equation for this reaction is:

Na2CO3 + H2SO4 → Na2SO4 + H2O + CO2

From this equation, we can see that one mole of Na2CO3 reacts with one mole of H2SO4. Therefore, the stoichiometry is 1:1.

Calculating Moles of Na2CO3

First, we need to calculate the number of moles of Na2CO3 in 0.125g. The molar mass of Na2CO3 is calculated as follows:

• Sodium (Na): 22.99 g/mol × 2 = 45.98 g/mol
• Carbon (C): 12.01 g/mol × 1 = 12.01 g/mol
• Oxygen (O): 16.00 g/mol × 3 = 48.00 g/mol

Adding these together gives:

Molar mass of Na2CO3 = 45.98 + 12.01 + 48.00 = 105.99 g/mol

Now, we can calculate the number of moles of Na2CO3 in 0.125g:

Number of moles = mass (g) / molar mass (g/mol) = 0.125 g / 105.99 g/mol ≈ 0.00118 moles

Finding Millimoles of Na2CO3

To convert moles to millimoles, we multiply by 1000:

Millimoles of Na2CO3 = 0.00118 moles × 1000 = 1.18 mmoles

Determining Millimoles of H2SO4 Required

Since the reaction ratio is 1:1, the number of millimoles of H2SO4 required will be the same as that of Na2CO3:

Millimoles of H2SO4 required = 1.18 mmoles

Concentration of H2SO4 Solution

Now, we need to consider the concentration of the H2SO4 solution. The solution is 0.1N, which means it has 0.1 equivalents per liter. Since sulfuric acid is a diprotic acid (it can donate two protons), 1N H2SO4 is equivalent to 0.5M. Therefore, 0.1N H2SO4 corresponds to 0.1 equivalents per liter.

To find out how many milliliters of this solution are needed to provide 1.18 mmoles of H2SO4, we can use the formula:

Milliliters = (millimoles required / normality) × 1000

Substituting in the values:

Milliliters = (1.18 mmoles / 0.1 N) × 1000 = 11.8 mL

Final Summary

In summary, to completely react with 0.125g of Na2CO3, you will need approximately 1.18 mmoles of 0.1N H2SO4, which translates to about 11.8 mL of the sulfuric acid solution. This calculation illustrates the importance of stoichiometry in chemical reactions and how to convert between different units of measurement effectively.