Last science question!! Thank you all for the help!

What are the primary responsibilities of a chemical engineer involved in "r& d"? develop large scale manufacturing operations discover new products and processes training of new chemists determine products needed by consumers

Sodium sulfate dissolves as follows: na2so4(s) → 2na+(aq) + so42- (aq). how many moles of na2so4 are required to make 1.0 l of solution in which the na concentration is 0.10 m?

Calculate the frequency of a wave in a spring toy. the wave has a speed of 1.1 meters per second and a wavelength of 0.1 meters. *