Multiple choice Water gas is prepared by passing ____. steam over white hot coke air over red hot coke methane over red hot coke steam over heated sulphur Reveal answer Fill a bubble to check yourself A Correct answer Explanation Water gas (CO + H2 mixture) is produced by passing steam over white-hot coke (carbon) at about 1000°C. The endothermic reaction is: C + H2O → CO + H2. This is an important industrial gas mixture.