Answer:
at the beginning:
pH = 0.745
Explanation:
HCl is a strong acid, so:
0.18 M 0.18 0.18.....equilibrium
before base is added:
∴ [ H3O+ ] ≅ <em>C </em>HCl = 0.18 M
⇒ pH = - Log [ H3O+ ] = - Log ( 0.18 )
⇒ pH = 0.745
Heat energy is required.
In distillation, the solution is first heated, where heat energy is required, such as using a bunsen burner.
When the solution is heated, the water may reach its boiling point and evaporate. However, salt does not. When water molecules evaporates, it travels through a condenser that cools it down into liquid again. Therefore we get pure water. Salt is also obtained in the original beaker.
Therefore to first start this process, heat energy is required.
Answer: The correct option is 2.
Explanation: Polyatomic ions are defined as the ions in which two or more elements are covalently bonded to act as a single unit. They always carry some charge.
Examples of polyatomic ions are: 
known as hydroxide ion, 
known as sulfate ion
We are given a compound 
having 2 ions which are 
and 
. these ions are named as sodium ions and hydrogen carbonate ions.
Therefore, the correct option is 2.
Answer: D.
Explanation: D. Acetone, Acetone may be rinsed over materials to wash off the explosive residue.
Hope this helps :)
