IELTS Academic Task 1 Sample Essay 26: Thermal Conductivity of Material at 25C
The line graph above compares the thermal conductivity of acetals, acetone, acetylene gas, acrylic, and atmospheric air at 25 degrees Celsius.
Acetone has the highest thermal conductivity of all the substances, at 1600 W/(m-K). Acetylene gas has the second highest conductivity, measuring nearly 1550 W/(m-K). Slightly below 1500 W/(m-K) are acetals, with the third highest conductivity. Next is air, which has a thermal conductivity of roughly 1425 W/(m-K). The least conductive material included in this graph is acrylic. The thermal conductivity of acrylic is just over 1350 W/(m-K).
Overall, the thermal conductivity of these six substances appears to vary quite widely, given the graphical representation. Only acetals and acetylene gas appear to be closer than 50 W/(m-K) apart in their level of conductivity. The difference between the most conductive material, acetone, and the least conductive material, acrylic, is nearly 250 W/(m-K). Further information, for instance a sampling of more materials, would be necessary to know how substantial this difference is.