4. Data: Substance H2O(l) CO2(g) Ethane, C2H6(g) Ethene, C2H4(g) DHfq/kJ mol-1 –285.5 –393 –83.6 +52.6 (a) Write equation for the complete combustion of: (i) ethane (ii) ethene (iii) hydrogen (b) Calculate the enthalpy of combustion in each case. (c) From the results obtained in (b), calculate the enthalpy change for the reaction: C2H4(g) + H2(g) ® C2H6(g)

Both josef loschmidt and amedeo avogadro contributed to our understanding of basic molecular numbers, sizes, and reaction ratios. neither scientist discovered “avogadro’s number” in the form we use it today (6.02 x 10 23). still, there’s a controversy over the name. research the contributions from these two scientists and read about how avogadro’s number got its name. briefly state what you think this number should be called, providing key details of each scientist’s contributions to this concept and a solid rationale for your case in naming the number.

What reaction is taking place? 02 + c3h8 = h20 + co2

This flow chart shows the amount of energy that is emitted by each type of light. ultraviolet > blue light > yellow light > red light (maximum energy) (minimum energy) in an experiment, shining which type of light on a strip of metal would be least likely to produce the photoelectric effect? ultraviolet light dim blue light bright red light bright yellow light