Chemistry
The reaction of potassium permanganate with acidified iron (II) sulphate is given below :
2KMnO4 + 10FeSO4 + 8H2SO4 ⟶ K2SO4 + 2MnSO4 + 5 Fe2(SO4)3 + 8H2O.
If 15.8 g. of potassium permanganate was used in the reaction, calculate the mass of iron (II) sulphate used in the above reaction.
[K = 39, Mn = 55, Fe = 56, S = 32, O = 16]
Related Questions
From the equation : (NH4)2 Cr2O7 ⟶ Cr2O3 + 4H2O + N2 Calculate :
(i) the vol. of nitrogen at STP, evolved when 63 g. of ammonium dichromate is heated.
(ii) the mass of Cr2O3 formed at the same time.
[N = 14, H = 1, Cr = 52, O = 16]
10 g. of a mixture of NaCl and anhydrous Na2SO4 is dissolved in water. An excess of BaCl2 soln. is added and 6.99 g. of BaSO4 is precipitated according to the equation :
Na2SO4 + BaCl2 → BaSO4↓ + 2NaCl.
Calculate the percentage of Na2SO4 in the original mixture.
[O = 16 ; Na = 23 ; S = 32; Ba = 137]
The equations given below relate to the manufacture of sodium carbonate [Mol. wt. of Na2CO3 = 106]
(i) NaCl + NH3 + CO2 + H2O ⟶ NaHCO3 + NH4Cl
(ii) 2NaHCO3 ⟶ Na2CO3 + H2O + CO2
Questions (a) and (b) are based on the production of 21.2 g. of sodium carbonate.
(a) What mass of sodium hydrogen carbonate must be heated to give 21.2 g. of sodium carbonate [Molecular weight of NaHCO3 = 84].
(b) To produce the mass of sodium hydrogen carbonate calculated in (a), what volume of carbon dioxide, measured at s.t.p., would be required.
The relative molecular mass [mol. wt.] of copper oxide is 80. What vol. of NH3 (measured at s.t.p.) is required to completely reduce 120 g of CuO.
[3CuO + 2NH3 ⟶ 3Cu + 3H2O + N2].