A can of aerosol deodorant contains one pound of a scented liquid that will vaporize and spray out when the top button is pushed. When 1oz of the substance (latent heat is 68 Btu/ lbm ) is vaporized, the energy needed for the change in phase of the substance comes from the stored energy of the remaining deodorant. How many degrees does the temperature of this remaining substance drop when 1 oz is sprayed?