## Chemistry: A Molecular Approach (3rd Edition)

$$-109^{o}F=-78.3^{o}C$$
Since we are given that $-109^{o}F$ is the temperature of dry ice, we can convert to $^{o}C$: $^{o}C = (-109^{o}F - 32)\div1.8 = -78.3^{o}C$