Shristi heated Ethanol with a compound A in presence of a few drops of concentrated sulphuric acid and observed a sweet-smelling compound B is formed. When B is treated with sodium hydroxide it gives back Ethanol and a compound C.
a) Identify A and C
b) Give one use for each of compounds A and B.
c) Write the chemical reactions involved and name the reactions.
Important Questions on Sample Paper 1
Two students decided to investigate the effect of water and air on iron objects under identical experimental conditions. They measured the mass of each object before placing it partially immersed in 10 ml of water. After a few days, the object was removed and dried and their masses were measured. The table shows their results.
| Student | Object | Mass of Object before Rusting in g | Mass of the object coated object in g |
| A | Nail | ||
| B | Thin Plate |
a) What might be the reason for the varied observations of the two students?
(b) In another set up the students coated iron nails with zinc metal and noted that, iron nails coated with zinc prevents rusting. They also observed that zinc initially acts as a physical barrier, but an extra advantage of using zinc is that it continues to prevent rusting even if the layer of zinc is damaged. Name this process of rust prevention and give any two other methods to prevent rusting.
In which of the following application of iron, rusting will occur most? Support your answer with valid reason.
A - Iron Bucket electroplated with Zinc
B - Electricity cables having iron wires covered with aluminium
C - Iron hinges on a gate
D - Painted iron fence
