Ibuprofen, an aspirin substitute, has a mass percent composition of 75.69% C, 8.80% H, and 15.51% O. Calculate its empirical formula.

C₁₃H₁₈O₂

Explanation:

Empirical formula is the simplest ratio in moles of the elements presents in the compound. Assuming a basis of 100g, we need to convert the mass of each element to moles and, find the ratio of each of these:

Moles C:

75.69g * (1mol / 12.01g) = 6.3 moles of C

Moles H:

8.80g * (1mol / 1.01g) = 8.7 moles of H

Moles O:

15.51g * (1mol / 16g) = 0.97 moles of O

The ratio dividing in the moles of O -Because is the element with the lower amount of moles-:

C = 6.3mol / 0.97mol = 6.5

H = 8.7mol / 0.97mol = 9

O = 0.97mol / 0.97mol = 1

As the ratio must be in whole-numbers, multiplying in 2:

C = 13;

H = 18

O = 2

And empirical formula is:

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.

i would say b

explanation:

but i think i would need more information than that