Why was the introduction of oxygen such a big deal?

What volume of a 2.00 m stock solution of naoh is needed to prepare 150. ml of 0.40 m solution?

Asample of air with a volume of 2.20m3 at a pressure of 105 kpa and a temperature of 30c is cooled to 10c and the pressure is reduced to 75.0 kpa. what is the new volume? 6.9 1.34 2.56 43.0 2.88

Surface currents are caused by blank space . question 14 options: surface currents are caused by? differences in water temperature high salinity differences in density wind forces