Suppose a new metallic element x is discovered, and its reactions with oxygen gas and chlorine gas at 298 k are studied. Trial reaction δhºrxn (kj/mol) 1 4x(s) 3o2(g) → 2x2o3(s) –600 2 2x(s) 3cl2(g) → 2xcl3(s) –800 3 4xcl3(s) 3o2(g) → 2x2o3(s) 6cl2(g) –200 however, it is later discovered that one of the samples was contaminated, and the δhºrxn value from this trial is not reliable. Which trial had the contaminated sample, and what should the correct value of δhºrxn be for this trial

the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.