Energy changes
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Making sense of energy changes helps chemists ot answer two very important questions: 'How fast?' and 'How far?'.
The definitions of energy quantities are very precise and so the study of this area of chemistry calls for close attention to detail.
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Recently Asked Questions
- I tried to plan and design an experiment to find the molar enthalpy change for the reaction between magnesium powder and aqueous copper(II) sulphate. I decided to measure the sulphate into a polystyrene cup and add an excess of magnesium powder, then record the temperature. What should I do next?
- What are the standard conditions required for standard enthalpy of combustion and formation. 220209
- A. To find the enthalpy change of displacement reaction between zinc and copper(II) ion, a graph was plotted (to find the temperature when zinc powder was added) to find the change of temperature. However, to find the enthalpy change of formation of calcium carbonate (by adding HCl (1M) into calcium metal and calcium carbonate respectively), just the highest temperatures were recorded. Why there is such difference between the two experiments? B. When dilute hydrochloric acid was added to calcium metal, white fumes were observed and a smell like burning fire crackers was detected. According to my limited knowledge, only hydrogen gas (colourless) and calcium chloride solution (colourless) would be formed. Why were there white fumes? 260109
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updated: 09 July 2003
