In qualitative analysis when H2S is passed through an aqueous solution of salt acidified with dil. HCl, a black precipitate is obtained. On boiling the precipitate with dil. HNO3, it forms a solution of blue colour. Addition of excess of aqueous solution of ammonia to this solution gives
(b) Black precipitate of copper sulphide is formed which gives blue colour of copper nitrate on boiling with dilute HNO3. When aqueous solution of ammonia is added to it, deep blue colour of
Match the formulas of oxides given in Column I with the type of oxide given in Column II and mark the correct option.
Match the compounds given in Column I with the hybridization and shape given in Column II and mark the correct option.
Write balanced equations for the following:
(i) NaCl is heated witlrsulphuric acid in the presence of MnO2
(ii) Chlorine gas is passed into a solution of Nal in water.
What are the oxidation states of phosphorus in the following: –
(i) H3PO3 (ii)PCl3
(iii) Ca3P2(iv)Na3PO4
(v) POF3
Write a balanced chemical equation, for the reaction showing catalytic oxidation of NH3 by atmospheric oxygen.
Why is BiH3 the strongest reducing agent amongst all the hydrides of group 15 elements? (C.B.S.E. 2013)
What happens when sulp’hur dioxide is passed through an aqueous solution of Fe(III) salt?
Why does nitrogen show catenation properties less than phosphorus ? (C.B.S.E. Foreign 2009)
Reduction potentials of some ions are given below. Arrange them in decreasing order of oxidizing power.
How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions . involved.
Why is BiH3 the strongest reducing agent amongst all the hydrides of Group 15 elements?
Give the formula and describe the structure of a noble gas species which is isostructural with: (i) ICI4– (ii) IBr2– (iii) Br03–
On addition of cone. H2SO4 to a chloride salt, colourless fumes are evolved but in case of iodide salt, violet fumes come out. This is because
Which of the following orders are correct as per the properties mentioned against each?
In PCl5, phosphorus is in sp3d hybridised state but all its five bonds are not equivalent. Justify your answer with reason.
In the ring test of NO3 ion.Fe2+ion reduces nitrate ion to nitric oxide, which combines with Fe2+ (aq.) ion to form brown complex. Write the reactions involved in the formation of brown ring.
Assertion (A): HNO3 makes from passive.
Reason (R): HNO3 forms a protective layer of ferric nitrate on the surface of iron.
