What would be the saturation concentration (mol/l) of oxygen in river in winter when the temperature is 5°c if the henry's law constant at this temperature is 1.90x103 mol/l-atm? what would be the answer in units of mg/l? plus: to see the effect of temperature on gas solubility and to practice with a different set of units, calculate the saturation concentration (in mg/l) at 20°c using a k value of 4.01x104 atm. for 5°c, 12.7 mg/l; for 20°c, 9.25 mg/l a

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.