C) A battery of emf, E drives a current of 0.25A when connected to a 5.5ohms resistor. When the 5.5ohms resistor is replaced with a 2.5ohms resistor, the current flowing becomes 0.5A.
Using E=V+Ir, Find the emf, E of the battery.

The molecular formula for caffeine is cshion402. which of the following elements is not found in caffeine?

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.

Chlorophyll a had the molecular formula c55h72mgn4o5 how many atoms are in this molecule