Question 5 :
Iron can liberate $H_2$ from dil. $H_2SO_4$ but copper cannot liberate $H_2$ from dil. $H_2SO_4$ because :

Question 8 :
If X is a non-metal, it will not conduct electricity unless it is carbon in the form of __________.

Question 9 :
________ is called a space age metal and used in military jets and spacecrafts.

Question 17 :
Compare the chemical properties of metals and non-metals with reference to ionization.<br/>

Question 20 :
State True or False.The process of heating concentrated ore to a high temperature in excess air is called&#160;Roasting. State whether it is &#160;true or false

Question 22 :
Paheli prepared a blue coloured solution of copper sulphate in beaker A and placed an iron nail in it. Boojho prepared a yellowish green solution of ferrous sulphate in beaker B and placed a copper wire in it. Changes they observe in the two beakers after an hour&#160;will be :<br/>

Question 23 :
Four students A, B, C and D took aqueous solutions of zinc sulphate and iron sulphate in two test tubes I and II and dropped metal pieces of Iron and Zinc in the two solutions. After several hours, they made observations and recorded their findings in the form of a table given below:<br/><table class="wysiwyg-table"><tbody><tr><td>Observation</td><td>Metal</td><td>Solution</td><td>Change in colour of the solution</td><td>Deposit/Residue obtained</td></tr><tr><td>By A</td><td>Fe</td><td>ZnSO$_4$</td><td>turned green</td><td>Silver grey coating</td></tr><tr><td></td><td>Zn</td><td>FeSO$_4$</td><td>no change</td><td>no change</td></tr><tr><td>By B</td><td>Fe</td><td>ZnSO$_4$</td><td>no change</td><td>black residue</td></tr><tr><td></td><td>Zn</td><td>FeSO$_4$</td><td>colour faded</td><td>grey coating</td></tr><tr><td>By C</td><td>Fe</td><td>ZnSO$_4$</td><td>no change</td><td>no change</td></tr><tr><td></td><td>Zn</td><td>FeSO$_4$</td><td>turned colourless</td><td>black residue</td></tr><tr><td>By D</td><td>Fe</td><td>ZnSO$_4$</td><td>no change</td><td>grey residue</td></tr><tr><td></td><td>Zn</td><td>FeSO$_4$</td><td>no change</td><td>black reside</td></tr></tbody></table>Who reported the correct observation?

Question 26 :
$100\ g$ of a metal carbonate is heated which completely dissociated and forms $22.4\ L$ of $CO_{2}$ at STP. The metal carbonate is?