Why don't trees spontaneously catch on fire and burn all the time? Why don't fires stop immediately as soon as they start? Develop a model for what has to happen for a large fire to occur.

The lattice enthalpy (formation of ionic solid from ions in the gas phase) for agcl(s) is -916 kj/mol and the hydration enthalpy (dissolution of gaseous ions into water) is -850 kj/mol. how much heat (in joules) is involved in forming 1l of saturated agcl solution (1.8 × 10-4 g / 100 ml water) by dissolving agcl(s)? assume solution volume does not change much upon dissolution. the equations are given below. ag+(g) + cl−(g) æ agcl(s)

50 points! need answer asap. what type of organic compound contains the following functional group? (2 points)

Give one example of a pure (exact) number and of an estimated (measured) number.