The purpose<span> of preparing </span>Set-up<span> _ is to act as a </span>control set-up<span> to ensure that the (measured variable) is only caused by the(changed variable) and not any other variables in the experiment.</span>
<span>The answer is A. In chemistry, Gibbs Free Energy is defined as the enthalpy of the system minus the product of the temperature times the entropy of the system. To write it as a formula, G = H - TS, delta G=delta H-T*delta S, where delta denotes the change.</span>
Methane is lighter than air, having a specific gravity of 0.554. It is only slightly soluble in water. It burns readily in air, forming carbon dioxide
and water vapour; the flame is pale, slightly luminous, and very hot.
The boiling point of methane is −162 °C (−259.6 °F) and the melting
point is −182.5 °C (−296.5 °F). Methane in general is very stable, but
mixtures of methane and air, with the methane content between 5 and 14
percent by volume, are explosive. Explosions of such mixtures have been
frequent in coal mines and collieries and have been the cause of many
mine disasters.
