a sunscreen preparation contains 2.5% per mass benzyl salicylate. if a tube contains 4oz of sunscreen, how many kg of benzyl salicylate are needed to manufacture 325 tubes?

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

Acompound contains c, h, and o atoms. when 1.130 g of the compound is burned in oxygen, 1.064 g co2 and 0.3631 g h2o are produced. what is the empirical formula of this compound?

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?