Chemistry
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]
Related Questions
Washing soda has the formula Na2CO3.10H2O. What mass of anhydrous sodium carbonate is left when all the water of crystallization is expelled by heating 57.2 g of washing soda.
Na2SO4 + Pb(NO3)2 ⟶ PbSO4 + 2NaNO3. When excess lead nitrate solution was added to a solution of sodium sulphate, 15.15 g of lead sulphate were precipitated. What mass of sodium sulphate was present in the original solution.
[H = 1 ; C = 12 ; O = 16 ; Na = 23; S = 32 ; Pb = 207]
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 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]