Question

[5]a) a water-insoluble calcium compound (a) on reacting with dil. H2so4released a colourless and odourless gas (b) with brisk effervescence.When gas (b) was passed through lime water, the lime water turned milkyand again formed compound



a. Identify a and b and write the chemicalequations for the reactions involved.B) a brown substance 'x' on heating in air forms a compound 'y'. Whenhydrogen gas is passed over 'y', it changes to 'x' again.I. Name substances 'x' and 'y'.Ii. Name the processes occurring during the two changes.Iii. Write the chemical equations involved.

Answer 1

X( BROWN ) + O2=XO( YELLOW)

XO+H2=X + H2O

As we know that iron oxide has yellow colour

Answer : X= Fe