$500 \ ml$ aqueous solution is prepared by dissolving $2$ moles of $HCl$ in water. What will be the molarity of this solution (in $M$)?

$(a)$ If we take hydrochloric acid and acetic acid of the same concentration,which one will produce a lower $H^{+}$ ion concentration? Out of the two,which one is a weak acid?
$(b)$ If someone is suffering from acidity,which of the following would you suggest to cure it: vinegar,orange juice,or baking soda solution? Give a reason for your answer.

What is the molecular mass of $NaOH$?

The compound which is used in glass, soap, and paper industries is:

The $pH$ scale is applicable to which of the following?

Crystals of copper sulphate are heated in a test tube for some time.
$(a)$ What is the colour of copper sulphate crystals:
$(i)$ before heating, and $(ii)$ after heating?