In our ChemE lab, we were asked to place a 25 cm x 25 cm x 1 cm (thick) block of wood in a water bath.....the rate of water absorption into the wood block is known to be 8 grams/100 cm^2 at 20 degrees C --- and the wood block is assumed to be at normalized ambient temp as well and completely dry or free of moisture before entering the water bath.

Now...when we change the temperature of the water bath from 20 degrees C to 30 degrees C, the rate of water absorption changed and the wood absorbed more water in the same unit time. Why??? Help me understand?

Second....When we pre-conditioned the block of wood and raised its temp to 30 degrees C before placing it in the 20 degree C water bath, it also absorbed more water than the original control....again why???