question_answer 6)

Fill in the blanks in the following statements. (a) When carbon dioxide is passed through lime water, it turns milky due to the formation of .......... (b) The chemical name of baking soda is ........ . (c) Two methods by which rusting of iron can be prevented are ...... and ......... . (d) Changes in which only ...... properties of a substance change are called physical changes. (e) Changes in which new substances are formed are called.  

Answer:

(a) calcium carbonate \[\underset{\text{Lime}\,\text{water}}{\mathop{Ca{{\left( OH \right)}_{2}}}}\,+\underset{\begin{smallmatrix} \text{Carbon} \\ \text{dioxide} \end{smallmatrix}}{\mathop{C{{O}_{2}}}}\,\xrightarrow[{}]{{}}\underset{\begin{smallmatrix} \text{Calcium} \\ \text{carbonate} \end{smallmatrix}}{\mathop{CaC{{O}_{3}}}}\,+\underset{\text{Water}}{\mathop{{{H}_{2}}O}}\,\] (b) sodium hydrogen carbonate (c) galvanization, painting (d) physical (e) chemical changes