Warming Ammonium chloride with sodium hydrochloride in a test tube is an example of
1). Open system
2). Closed system
3). Isobaric system
4). Isothermal system
2. Which of the following is not a precious semiprecious stone?
3. An example of heterocyclic compound is
4. Question 14.23:The two strands in DNA are not identical but are complementary. Explain.
5. The substance which does not expand on going from liquid state to solid state is
6. Magnesium (Mg) + Oxygen $(O_{2})$ = ?
7. An example of replenishable energy source is–
9. Iron is prevented from rusting by coating with zinc. This process is called as