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a 25cm³ aliquot of ammonium iron(ii) tetraoxomanganate(vii) containing 32.9g of its salt in 250cm³ solution, needed 25cm³ of potassium tetraoxomanganate(vii) solution for a
colour change to occur. what is the concentration of the potassium tetraoxomanganate(vii) solution jiskha
To find the concentration of the potassium tetraoxomanganate(VII) solution, you need to use the information given regarding the volume of the solution and the amount of the ammonium iron(II) tetraoxomanganate(VII) salt.
Let's break down the problem and the steps to find the concentration:
1. Determine the number of moles of ammonium iron(II) tetraoxomanganate(VII) (NH4)2Fe(MnO4)4 in the given 25cm³ aliquot.
To do this, you need to use the molar mass of the salt, which can be calculated by adding up the molar masses of each element:
Molar mass of ammonium iron(II) tetraoxomanganate(VII) = (2 x molar mass of NH4) + molar mass of Fe + (4 x molar mass of MnO4)
You can find the molar masses of NH4, Fe, and MnO4 from the periodic table. Calculate this value to find the molar mass.
2. Once you have the molar mass of ammonium iron(II) tetraoxomanganate(VII), use it to calculate the number of moles of the salt in the 25cm³ aliquot.
Moles = Mass / Molar mass
In this case, the mass is given as 32.9g.
3. Use the molar ratio between potassium tetraoxomanganate(VII) and ammonium iron(II) tetraoxomanganate(VII) from the balanced chemical equation to find the number of moles of potassium tetraoxomanganate(VII) (KMnO4).
The balanced chemical equation could be something like:
2KMnO4 + (NH4)2Fe(MnO4)4 → 2MnO2 + Fe(NH4)2(MnO4)4 + K2SO4
The ratio between KMnO4 and (NH4)2Fe(MnO4)4 is 2:1 based on the coefficients in the balanced equation.
4. Calculate the number of moles of KMnO4 in the 25cm³ aliquot using the molar ratio.
5. Finally, determine the concentration of the potassium tetraoxomanganate(VII) solution in mol/dm³ (M). This is done by dividing the number of moles of KMnO4 in the 25cm³ aliquot by the volume of the potassium tetraoxomanganate(VII) solution used (25cm³).
Remember to convert the volume to dm³ by dividing by 1000.
By following these steps, you should be able to calculate the concentration of the potassium tetraoxomanganate(VII) solution.