What happens when hot concentrated HNO3 is placed in an iron vessel? Answer: Iron reacts with hot concentrated HNO3 to produce ferric nitrate, nitrogen dioxide and water. Fe + 6HNO3 = Fe (NO3)3 + 3NO2 ↑ + 3H2O

What happens when ammonia gas is passed over hot sodium? Answer: Passing dry ammonia gas over heated sodium forms solid sodamide. and hydrogen gas is released. 2NH3 + 2Na = 2NaNH2 + H2 ↑

What happens when concentrated sulfuric acid is added to sugar? Answer: When concentrated H2SO4 is added to sugar, the H2SO4 absorbs all the water content of the sugar and the sugar is converted to carbon. So the sugar turns black. C12H22O11 + [H2SO4 ] = 12C + [11H2O + H2SO4 ]

What happens when excess carbon dioxide is driven into clear limewater? Answer: Passing CO2 through clear limewater, first produces insoluble white calcium carbonate. As a result, lime water becomes cloudy. Ca(OH)2 + CO2 = CaCO3 ↓ + H2O Passing excess CO2 through this turbid lime water turns the insoluble calcium carbonate into soluble calcium bicarbonate.

What happens when H2S is added to acidified potassium dichromate solution? Answer: When hydrogen sulphide (H2S) is added to an orange solution of acidified potassium dichromate (K2Cr2O7), a green chloric salt is formed. As a result, the colour of the solution turns green. H2S is oxidized and sulfur is precipitated. K2Cr2O7 + 4H2SO4 + 3H2S

What happens when concentrated HNO3 is dropped on hot charcoal? Answer: When concentrated HNO3 is dropped (drop by drop) on hot charcoal (carbon), carbon oxidizes to CO2 gas and HNO3 reduces to nitrogen dioxide (NO2). C + 4HNO3 = CO2 ↑ + 4NO2 ↑+ 2H2O

What happens when copper metal is reacted with concentrated HCL in the presence of oxygen? Answer: Copper reacts slowly with concentrated and hot HCI in the presence of oxygen to produce cupric chloride and water. 2Cu + 4HCl + O2 = 2CuCl2 + 2H2O

What happens when Copper is boiled with concentrated nitric acid? Answer: Boiling copper with concentrated nitric acid produces cupric nitrate, nitrogen dioxide and water. Cu + 4HNO3 = Cu(NO3)2 + 2NO2↑ + H2O

What happens when Copper is boiled with concentrated sulfuric acid? Answer: Boiling copper with strong sulfuric acid produces copper sulphate, sulfur dioxide and water. Cu + 2H2SO4 = CuSO4 + SO2 ↑ + 2H20

What happens when iron reacts with hot concentrated nitric acid? Answer: Iron reacts with hot dark nitric acid to produce ferric nitrate and nitrogen dioxide. Fe + 6HNO3 = Fe(NO3)3 + 3NO2 + 3H2O