Which statement best describes the roles of photosynthesis and respiration in the carbon cycle?

What is the empirical formula of a compound that is 50.7% antimony and 49.3% selenium ?

High-pressure liquid chromatography (hplc) is a method used in chemistry and biochemistry to purify chemical substances. the pressures used in this procedure range from around 500 kilopascals (500,000 pa) to about 60,000 kpa (60,000,000 pa). it is often convenient to know the pressure in torr. if an hplc procedure is running at a pressure of 1.03×108 pa , what is its running pressure in torr?

Idont understand it 1.what is the boiling point of a solution of 675 grams of ethylene glycol (c2h6o2) in 2.50 liters of water?