What do you observe when
1. Sodium is dropped in cold water,
2. red lead is strongly heated,
3. copper carbonate is heated strongly,
4. potassium iodide is added to lead nitrate,
5. Hydrochloric acid is added to silver nitrate
Answers
Answer:
1. When sodium is dropped in cold water, it reacts explosively and burns with a golden yellow flame. The reaction is exothermic and vigourus. It form sodium hydroxide with the liberation of hydrogen gas.
2.Red Lead is Pb3O4 which is a orange-red solid. When heated strongly, it turns reddish brown when hot and yellow when cold due to formation of PbO and O2.
3. When green copper carbonate{CuCO3} is heated it decomposes forming copper oxide {CuO} and carbon dioxide {CO2}.
4. When a solution of potassium iodide is added to a solution of lead nitrate taken in a test tube, the precipitation of a yellowish solid is observed. This yellowish solid is lead iodide. Potassium nitrate is formed along with lead iodide. This is a double displacement reaction.
5. Addition of silver nitrate to hydrochloric acid, gives an insoluble precipitate of the respective chloride, This precipitate is soluble in ammonium hydroxide and insoluble in dilute nitric acid.
Answer:
1) When sodium is dropped in cold water, it reacts explosively and burns with a golden yellow flame. The reaction is exothermic and vigourus. It form sodium hydroxide with the liberation of hydrogen gas.
2) Red Lead is Pb3O4 which is a orange-red solid. When heated strongly, it turns reddish brown when hot and yellow when cold due to formation of PbO and O2.
3) This type of reaction is called thermal decomposition . Copper carbonate is green and copper oxide is black. You can see a colour change from green to black during the reaction. The carbon dioxide produced can be detected using limewater, which turns milky.
4) When a solution of potassium iodide is added to a solution of lead nitrate taken in a test tube, the precipitation of a yellowish solid is observed. This yellowish solid is lead iodide. Potassium nitrate is formed along with lead iodide. This is a double displacement reaction.
5) When a hydrochloric acid is added to silver nitrate solution then a curdy white ppt is formed.
Explanation:
hope it helps you : )