Could someone help with question 2 please

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

Which formula can be used to calculate the molar mass of hydrogen peroxide

An engineer decides to use a slightly weaker material rather than a stronger material, since she knows that the stronger material can break suddenly. this is an example of what? a choosing a material that will show warning before it fails b using composite materials that combine strength c using a material for multiple applications d using design techniques that increase efficiency and reduce cost