How much heat is released when a 30.0 g sample of CO2 is cooled from an initial temperature of 20.0°C to -95.0°C?

Question

aaronq · Answer

you have use $q=mC_p\Delta T$

where q is heat, m is mass, $C_p$ is the specific heat capacity of carbon dioxide (solid i suppose), and $\Delta T$ is the change in temp

zned6559 · Answer

that's not right there's more to it

aaronq · Answer

Oh right, sorry i didn't see such a large change in temperature. You have to basically use the equation 3 times (once for every phase) and add the latent heat for the solid-liquid and liquid-gas transitions. This graph sums it up

|dw:1450230880677:dw|

aaronq · Answer

|dw:1450231122512:dw|

for the unshaded areas use the equation i provided to you initially (different specific heat capacities) and for the shaded use $\sf  q=m*H_{fusion~or ~vaporization}$