Asealed vessel containg helium, chlorine and fluorine has a total pressure of 205 kpa and partial pressures of 15 kpa for chlorine and 89 kpa for fluorine. what is the pressure for helium in kpa

According to Dalton's law of partial pressure

The total pressure of a mixture of ideal gases is sum of the partial pressures of each gas present in the mixture

So if we know the partial pressure of all the gases we can determine the total pressure of the mxiture by adding all of them.

Thus

Ptotal = PCl2 + PF2 + PHe

Thus

Partial pressure of helium = 205 - ( 89 + 15) = 101 kPa

101 kPa

Explanation:

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.