Advertisements
Advertisements
Question
The reaction of potassium permanganate (VII) with acidified iron (II) sulphate is given below:
2KMno4 + 10FeSO4 + 8H2O → K2SO4 + 2MnSO4 + 5Fe2(SO4)3 + 8H2O
If 15.8g of potassium permanganate (VII) was used in the reaction, calculate the mass of iron (II) sulphate used in the above reaction.
Advertisements
Solution
Molecular weight of KMnO4 = 39 + 55 + 16 x 4 = 158
Molecular weight of K2SO4 = 2 x 39 + 32 + 16 x 4 = 174
Molecular weight of FeSO4 = 56 + 32 + 64 = 152
2 x 158g of KMnO4 yields= 174g of K2SO4.
So, 15.8g of KMnO4 will yield = 174 x 15.8/2 x 158 = 8.7g of K2SO4 .
174g of K2SO4 yields 152g of FeSO4
So, 8.7 g of K2SO4 will yield = 152 x 8.7/174 = 7.6 g of FeSO4.
Hence, 7.6g of iron (II) sulphate is used in the above reaction.
APPEARS IN
RELATED QUESTIONS
Prove the Following :
2 X V.D. = Molecular mass.
Calculate the relative molecular mass of Potassium chlorate.
(use K = 39, Cl = 35.5, O = 16, C = 12, H = 1, Na = 23, N = 14, S=32)
Empirical formula of a compound is CH2O. If its empirical formula is equal to its vapour density, calculate the molecular formula of the compound.
If the relative molecular mass of A is 90, what is the molecular formula of A?
If a crop of wheat removes 20 Kg of nitrogen per hectare of soil, what mass of the fertilizer calcium nitrate,Ca(NO3)2 would be required to replace nitrogen in 10 hectare field? (N = 14, O = 16, Ca = 40)
Washing soda has the formula Na2CO3.10H2O.What is the mass of anhydrous sodium carbonate left when all the water of crystallization is expelled by heating 57.2 g of washing soda?
Calculate the relative molecular mass of:
(NH4)2SO4
Calculate the relative molecular mass of:
CH3COONa
A gas cylinder can hold 1 kg of hydrogen at room temperature and pressure. What mass of carbon dioxide can it hold under similar conditions of temperature and pressure?
When heated, potassium permanganate decomposes according to the following equation :
\[\ce{2KMnO4 -> \underset{\text{solid residue}}{K2MnO4 + MnO2} + O2}\]
(a) Some potassium permanganate was heated in the test tube. After collecting one litre of oxygen at room temperature, it was found that the test tube had undergone a loss in mass of 1.32 g. If one litre of hydrogen under the same conditions of temperature and pressure has a mass of 0.0825 g, calculate the relative molecular mass of oxygen.
(b) Given that the molecular mass of potassium permanganate is 158. What volume of oxygen (measured at room temperature) would be obtained by the complete decomposition of 15.8 g of potassium permanganate? (Molar volume at room temperature is 24 litres)
