# How do you calculate the energy absorbed when 2.0x10^3g of ice (CO_2) sublimate at the normal dry sublimation point? The enthalpy of sublimation 196.3J/g.

Nov 8, 2016

We want the energy required for the transition:

$C {O}_{2} \left(s\right) + \Delta \rightarrow C {O}_{2} \left(g\right)$

#### Explanation:

We assume that the temperature of the gas and the solid are EQUAL.

And thus we simply have to work out the product:

$2 \times {10}^{3} \cdot \cancel{g} \times 196.3 \cdot J \cdot \cancel{{g}^{-} 1}$ to get an answer in $\text{Joules}$ as required.

What would be the energy change for the reverse transition:

$C {O}_{2} \left(g\right) + \rightarrow C {O}_{2} \left(s\right)$?