A 0.21 g of Sulfuris acid is dissolved completely in sufficient water to make 0.25 litre of final solution. Calculate the hydrogen ion concentration (in mol 1 -1) in this solution. Give your answer in scientific notation to an appropriate number of significant figures. Remember to show successive steps and explain reasoning.
Please help, I'm really stuck!!
I have answered this three times. I will be happy to critique your thinking.
To calculate the hydrogen ion concentration in the solution, you need to use the chemical equation and the molar mass of sulfuric acid (H2SO4).
The chemical equation for sulfuric acid (H2SO4) dissolving in water can be written as:
H2SO4 -> 2H+ + SO4^2-
From the equation, you can see that one molecule of sulfuric acid dissociates to form two hydrogen ions (H+).
Step 1: Calculate the number of moles of sulfuric acid (H2SO4) in the given 0.21 g.
To calculate the number of moles, you need to divide the mass of the substance by its molar mass.
The molar mass of H2SO4 can be calculated as follows:
2(1.008 g/mol) + 32.07 g/mol + 4(16.00 g/mol) = 98.09 g/mol
Now, divide the mass of sulfuric acid by its molar mass:
0.21 g / 98.09 g/mol = 0.002142 mol
Step 2: Determine the concentration in moles per liter (mol/L).
Given that the final volume of the solution is 0.25 liters, divide the number of moles by the volume:
0.002142 mol / 0.25 L = 0.008568 mol/L
Step 3: Convert the concentration to scientific notation.
To express the answer in scientific notation, determine the appropriate number of significant figures based on the given information. In this case, use three significant figures.
0.008568 mol/L can be written in scientific notation as 8.57 × 10^-3 mol/L (rounded to three significant figures).
Therefore, the hydrogen ion concentration in this solution is 8.57 × 10^-3 mol/L.