Assignment – 6
Chemical Reactions And Equations

Q 35. When a green iron salt is heated strongly its colour finally changes to black and odour of burning sulphur is given out.
i.     Name the iron salt.
ii.    Name the type of reaction that take place.
iii.  Name the compound which changes into Brownish black colour.
iv.  Name the compound which is responsible for its odour.
v.   Write the chemical equation of the above statement.

Q36. Convert the statement into balanced equations by hit and trial method.

Q 37. Balance the following skeleton equation by hit and trial method.          

Q 38. A chemical is heated in a test tube brown fumes comes out and a black residue is left behind. 
(i) Name the chemical which gives brown fumes. 
(ii) Write the equation. 
(ii) Name the compound which gives black residue.

Q 39. Why respiration is exothermic reaction?

Q 40. What is thermite reaction ? Mention its use 

Q 41. What do you observe when a solution of lead nitrate and potassium iodide in water are mixed together? 

Q 42. Write balanced equations with state of reactants and products 
(i). Molten sodium chloride on passing current decomposes into sodium metal and chlorine gas 
(ii). Magnesium metal and hydrochloric acid react to product magnesium chloride and hydrogen. 
(iii). Potassium chlorate on heating produces potassium chloride and oxygen gas. 
(iv). Solutions of barium chloride and sodium sulphate react to produce ppt of barium sulphate and sodium chloride.
(v). Iron metal dissolves in copper sulphate solution forming iron sulphate and copper.