Which of the following reacts with water with the highest rate?

Which one of the following statements is not correct?

Which process is associated with the production of sodium carbonate?

Why is $Li_{2}CO_{3}$ decomposed at a lower temperature whereas $Na_{2}CO_{3}$ at a higher temperature?

Sodium carbonate is manufactured by the Solvay process. The products that are recycled are:

Fill in the blanks:
$(1)$ ......... method is used to prepare sodium carbonate.
$(2)$ Sodium carbonate exists as .........
$(3)$ Sodium chloride is commonly known as .........
$(4)$ Sodium chloride melts at ......... temperature.