Define the SI unit fro length, mass time , and temperature

A6.10 m nacl can be made by adding [x]g of nacl to a container and making the volume of water up to the 1.00 l line

If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?

If i initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a temperature of 200 k, and then i raise the pressure to 14 atm and increase the temperature to 300 k, what is the new volume of the gas?