When hydrogen is passed over a black solid compound A, the products are 'a colourless liquid' and 'a reddish brown metal B.' Substance B is divided into two parts, each placed in separate test tubes. Dilute HCl is added to one part of substance B and dilute HNO3, to the other.
Name the substances A and B.

When hydrogen is passed over a black solid compound A, the products are 'a colourless liquid' and 'a reddish brown metal B.' Substance B is divided into two parts, each placed in separate test tubes. Dilute HCl is added to one part of substance B and dilute HNO, to the other. What happens to substance A when it reacts with hydrogen ? Give reasons for your answer.

When hydrogen is passed over a black solid compound A, the products are 'a colourless liquid' and 'a reddish brown metal B.' Substance B is divided into two parts, each placed in separate test tubes. Dilute HCl is added to one part of substance B and dilute HNO, to the other. Is there any reaction between substance B and dilute hydrochloric acid ? Give reasons for your answer.

When hydrogen is passed over a black solid compound A, the products are 'a colourless liquid' and 'a reddish brown metal B.' Substance B is divided into two parts, each placed in separate test tubes. Dilute HCl is added to one part of substance B and dilute HNO, to the other. Write an equation for the reaction between hydrogen and substance A.

When hydrogen is passed over a black solid compound A, the products are .a colourless liquid. and .a reddish brown metal B.. Substance B is divided into two parts, each placed in separate test tubes. Dilute HCl is added to one part of substance B and dilute HNO_3 to the other. Is there any reaction between substance B and dilute hydrochloric acid ? Give reasons for your answer.

When hydrogen is passed over a black solid compound A, the products are .a colourless liquid. and .a reddish brown metal B.. Substance B is divided into two parts, each placed in separate test tubes. Dilute HCl is added to one part of substance B and dilute HNO_3 to the other. Give two tests for the colourless liquid formed in the experiment. What does it signifies ?

When diemethyl glyoxime is added to the aqueous solution of nickel (II) chloride in presence of dilute ammonia solution, a bright red coloured precipitate is obtained . (a) Draw the structure of bright red substance . (b) Write the oxidation state of nickel in the substance and hybridisation. (c ) State whether the substance is paramagnetic or diamagnetic.

Iron filings and sulphur were mixed together and divided into two parts, 'A' and 'B'. Part 'A' was heated strongly while part 'B' was not heated. Dilute hydrochloric acid was added to both the parts and evolution of gas was seen in both the cases. How will you identify the gases evolved?

A substance changes from its solid state to the liquid state when heat is supplied to it. (a) Name the process. (b) What name is given to heat observed by the substance. (c) How does the average kinetic energy of molecules of the substnace change ?

An organic liquid 'A' containing C,H and O with boiling point 78^(@)C , possessing a rather pleasant odous. On heating with concentrated sulphuric acid gives a gaseous product 'B' with the empirical formula CH_(2) 'B' decolourises bromine water as well as alkaline permanganate solution and takes up one mole of H_(2) (per mole of B) in presence of finely divided nickel at high temperature. Identify the substances A and B.

A reddish brown coloured metal is used in electrical wires. When powdered and heated strongly in an open china dish, its colour turns black. When hydrogen gas is passed over this black substance, it regains its original colour. Based on the above information, answer the following question. (i) Name the metal and the black coloured substance formed. (ii) Write balanced chemical equations for both the reactions.