Calculate the mole fraction of solute in 2 molal solution

When an object falls through the air and encounters air resistance its overall speed will be than if it had not encountered air resistance? (one word answer)

What is the mass of sodium in 3 moles of sodium chloride

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.