Suppose that coal of density 1.5 g/cm3 is pure carbon. (It is, in fact, much more com- plicated, but this is a reasonable ?rst approximation.) The combustion of carbon is described by the equation C(s) + O2 (g) -→ CO2 (g) ?H ? = -394 kJ What is the value of q (heat) when a lump of coal of size 7.9 cm × 7.4 cm × 6.9 cm is burned? What mass of water can be heated from 16 C to 100 C by burning this piece of coal? Answer in units of g.