Meta-analysis - Revision history

en>Qwfp: Undid revision 637416140 by StoneProphet11 (talk) Let's wait until these have been published in a peer-reviewed journal and cited by other researchers.

2014-12-10T07:39:51Z

Undid revision 637416140 by StoneProphet11 (talk) Let's wait until these have been published in a peer-reviewed journal and cited by other researchers.

← Older revision		Revision as of 09:39, 10 December 2014
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	I ~~like Slot Car Racing~~. ~~Appears boring? Not!<br>~~I ~~to learn Dutch in my free time~~.<br><br>~~Here is~~ my ~~weblog ...~~ [http://~~Goodc~~.net/~~?document_srl=60268 Fifa Coin generator~~]		Greetings! I am Marvella and I really feel comfy when people use the complete title. Body developing is what my family and I appreciate. I am a meter reader. California is our birth location.<br><br>Feel free to visit my site; [http://jvpsweden.net/solid-advice-for-getting-through-a-candida-albicans/ home std test kit]

161.130.188.79 at 16:02, 11 February 2014

2014-02-11T16:02:41Z

← Older revision		Revision as of 18:02, 11 February 2014
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	The '''standard enthalpy of combustion''' is the [[enthalpy]] change when one [[mole (unit)\|mole]] of a reactant completely burns in excess oxygen under [[Standard conditions for temperature and pressure\|standard thermodynamic conditions]] (although experimental values are usually obtained under different conditions and subsequently adjusted). ~~By definition, the combustion reactions are always particularly [[exothermic]] and so enthalpies of combustion are always negative, although the values for individual combustions may vary.~~		I like Slot Car Racing. Appears boring? Not!<br>I to learn Dutch in my free time.<br><br>Here is my weblog ... [http://Goodc.net/?document_srl=60268 Fifa Coin generator]

	~~The most common way of calculating the enthalpy change of combustion (or formation) is by using a Hess cycle or by using numerical based bond enthalpies. It is commonly denoted as~~ <~~math>\Delta H ^{\circ} _{\mathrm{comb}}</math> or <math>\Delta H ^{\circ}_{\mathrm{c}}</math~~>.
	~~When the enthalpy required is not a combustion, it can be denoted as~~ <~~math~~>~~\Delta H ^{\circ} _{\mathrm{total}}~~<~~/math~~>. Enthalpies of combustion are typically measured using [[calorimeter\|bomb calorimetry]], and have units of energy (typically kJ); strictly speaking, the enthalpy change per mole of substance combusted is ~~the standard ''molar'' enthalpy of combustion (which typically would have units of kJ mol<sup>−1</sup>)~~.

	~~== Alcohols and alkanes ==~~
	~~For alcohols and alkanes containing the same number of carbon atoms, e~~.g. [[methane]] (CH<sub>4</sub>) and [[methanol]] (CH<sub>3</sub>OH), for which the standard enthalpy change of the alkane would be more negative than the alcohol (<math>\Delta H ^{\circ}_{\mathrm{c}} [\mathrm{CH_{4 (g)}}]</math> = −890.3 kJ mol<sup>−1</sup>, <math>\Delta H ^{\circ}_{\mathrm{c}}[\mathrm{CH_3OH_{(l)}}]</math> = −726.0 kJ mol<sup>−1</sup>).

	Since the complete combustion of both of these carbon compounds produce carbon dioxide (CO<sub>2</sub>) and water (H<sub>2</sub>O), there is more bond-breaking and bond-making when methane is burnt. The presence of an [[Hydroxide\|-OH]] bond on methanol means that there is less bond-breaking and bond-making to produce water compared to methane.<ref>Edexcel AS Chemistry by Ann Fullick and Bob McDuell</ref>

	~~==References==~~
	~~{{reflist}}~~

	~~==External links==~~
	* [http://~~webbook~~.~~nist.gov~~/~~chemistry/ NIST Chemistry WebBook]~~

	~~[[Category:Enthalpy]~~]

	~~{{chem-stub}}~~

76.126.58.150 at 19:15, 11 January 2014

2014-01-11T19:15:32Z

← Older revision		Revision as of 21:15, 11 January 2014
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	~~Nice to satisfy you~~, ~~I am Marvella Shryock. Puerto Rico is where he~~ and ~~his wife reside~~. The ~~favorite pastime for my kids and me~~ is ~~to perform baseball but I haven't produced~~ a ~~dime with it~~. ~~I am~~ a ~~meter reader but I strategy on altering~~ it.<br><br>~~Here is my website ::~~ [~~http:~~//~~socialthat~~.~~extor~~.~~org~~/~~blogs~~/~~147240~~/~~144993/cures~~-~~for~~-~~any~~-~~candida~~-~~albicans-suggestions~~-to-~~use-now over the counter std test]~~		The '''standard enthalpy of combustion''' is the [[enthalpy]] change when one [[mole (unit)\|mole]] of a reactant completely burns in excess oxygen under [[Standard conditions for temperature and pressure\|standard thermodynamic conditions]] (although experimental values are usually obtained under different conditions and subsequently adjusted). By definition, the combustion reactions are always particularly [[exothermic]] and so enthalpies of combustion are always negative, although the values for individual combustions may vary.

			The most common way of calculating the enthalpy change of combustion (or formation) is by using a Hess cycle or by using numerical based bond enthalpies. It is commonly denoted as <math>\Delta H ^{\circ} _{\mathrm{comb}}</math> or <math>\Delta H ^{\circ}_{\mathrm{c}}</math>.
			When the enthalpy required is not a combustion, it can be denoted as <math>\Delta H ^{\circ} _{\mathrm{total}}</math>. Enthalpies of combustion are typically measured using [[calorimeter\|bomb calorimetry]], and have units of energy (typically kJ); strictly speaking, the enthalpy change per mole of substance combusted is the standard ''molar'' enthalpy of combustion (which typically would have units of kJ mol<sup>−1</sup>).

			== Alcohols and alkanes ==
			For alcohols and alkanes containing the same number of carbon atoms, e.g. [[methane]] (CH<sub>4</sub>) and [[methanol]] (CH<sub>3</sub>OH), for which the standard enthalpy change of the alkane would be more negative than the alcohol (<math>\Delta H ^{\circ}_{\mathrm{c}} [\mathrm{CH_{4 (g)}}]</math> = −890.3 kJ mol<sup>−1</sup>, <math>\Delta H ^{\circ}_{\mathrm{c}}[\mathrm{CH_3OH_{(l)}}]</math> = −726.0 kJ mol<sup>−1</sup>).

			Since the complete combustion of both of these carbon compounds produce carbon dioxide (CO<sub>2</sub>) and water (H<sub>2</sub>O), there is more bond-breaking and bond-making when methane is burnt. The presence of an [[Hydroxide\|-OH]] bond on methanol means that there is less bond-breaking and bond-making to produce water compared to methane.<ref>Edexcel AS Chemistry by Ann Fullick and Bob McDuell</ref>

			==References==
			{{reflist}}

			==External links==
			* [http://webbook.nist.gov/chemistry/ NIST Chemistry WebBook]

			[[Category:Enthalpy]]

			{{chem-stub}}

24.46.187.53: /* Advantages of meta-analysis */ if -> whether

2012-08-27T00:14:39Z

Advantages of meta-analysis: if -> whether

New page

Nice to satisfy you, I am Marvella Shryock. Puerto Rico is where he and his wife reside. The favorite pastime for my kids and me is to perform baseball but I haven't produced a dime with it. I am a meter reader but I strategy on altering it.<br><br>Here is my website :: [http://socialthat.extor.org/blogs/147240/144993/cures-for-any-candida-albicans-suggestions-to-use-now over the counter std test]