Energetics
Gbogbo ọrọ náà
Some reactions release heat and warm their surroundings; others absorb heat and feel cold to the touch. Understanding the energy changes in chemical reactions is essential for everything from choosing fuels to designing hand warmers.
In this lesson you will learn the difference between exothermic and endothermic reactions, how to measure energy changes using simple calorimetry, and how to calculate heat energy using Q = mc delta T.
Ebumnobi
- Know that chemical reactions in which heat energy is given out are described as exothermic, and those in which heat energy is taken in are described as endothermic
- Describe simple calorimetry experiments for reactions such as combustion, displacement, dissolving and neutralisation
- Calculate the heat energy change from a measured temperature change using the expression Q = mcDeltaT
- Investigate temperature changes accompanying salts dissolving in water, neutralisation reactions, displacement reactions and combustion reactions
Maapụ uche
E seela isiokwu a ka ị hụ otu echiche si ejikọta.
Mepee maapụ uche na ngwa
Kaadị ncheta
Omume ncheta ngwa ngwa n'ihe a na-anwale n'isiokwu a.
Mee omume kaadị ndị a na ngwa
Akwụkwọ Ọmụmụ
Ndetu Nkuzi Zuru Ezu di na Ngwa Green Bridge
Nweta ngwa Green Bridge CBT na ekwenti gi ma o bu kompiuta maka ulo akwukwo IGCSE zuru oke: akwukwo ule ndi gara aga, usoro nyocha, eserese uche, kaadi omumu na nkuzi olu.
Nnyocha Ọmụmụ
Ekele diri gi maka imecha ihe karịrị na Energetics. Ugbu a na ị na-enyochakwa isi echiche na echiche ndị dị mkpa, ọ bụ oge iji nwalee ihe ị ma. Ngwa a na-enye ụdị ajụjụ ọmụmụ dị iche iche emebere iji kwado nghọta gị wee nyere gị aka ịmata otú ị ghọtara ihe ndị a kụziri.
Ị ga-ahụ ngwakọta nke ụdị ajụjụ dị iche iche, gụnyere ajụjụ chọrọ ịhọrọ otu n’ime ọtụtụ azịza, ajụjụ chọrọ mkpirisi azịza, na ajụjụ ede ede. A na-arụpụta ajụjụ ọ bụla nke ọma iji nwalee akụkụ dị iche iche nke ihe ọmụma gị na nkà nke ịtụgharị uche.
Jiri akụkụ a nke nyocha ka ohere iji kụziere ihe ị matara banyere isiokwu ahụ ma chọpụta ebe ọ bụla ị nwere ike ịchọ ọmụmụ ihe ọzọ. Ekwela ka nsogbu ọ bụla ị na-eche ihu mee ka ị daa mba; kama, lee ha anya dị ka ohere maka ịzụlite onwe gị na imeziwanye.
- An exothermic reaction: A) Absorbs heat B) Releases heat C) Has no energy change D) Always involves combustion Answer: B
- The specific heat capacity of water is: A) 4.2 J/g/degrees C B) 42 J/g/degrees C C) 0.42 J/g/degrees C D) 420 J/g/degrees C Answer: A
- Which of these is an endothermic process? A) Combustion of methane B) Neutralisation C) Thermal decomposition of calcium carbonate D) Rusting of iron Answer: C
- In a calorimetry experiment, the temperature of 100 g of water rises by 10 degrees C. The energy transferred is: A) 420 J B) 1000 J C) 4200 J D) 42000 J Answer: C
- A cold pack works because the reaction inside is: A) Exothermic B) Endothermic C) Neutral D) Reversible Answer: B
Rue ajuju ndi a n'ime ngwa ahu
Rue ajuju ndi a n'ime ngwa ahu
Akwụkwọ A Na-atụ Aro
Mụtakwuo ihe site na isi mmalite mepere emepe
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Akụkụ akwụkwọ
Energy Basics
Define energy, distinguish types of energy, and describe the nature of energy changes that accompany chemical and physical changes
"Chemistry: Energy Basics" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/chemistry/pages/5-1-energy-basics. Access for free at https://openstax.org/books/chemistry/pages/1-introduction
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Akụkụ akwụkwọ
Enthalpy
State the first law of thermodynamics
"Chemistry: Enthalpy" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/chemistry/pages/5-3-enthalpy. Access for free at https://openstax.org/books/chemistry/pages/1-introduction
Ndị otu ndị ọzọ bipụtara ha n'okpuru ikike mepere emepe, anyị na-ekele ha dị ka ha si chọọ. Njikọ na-emepe saịtị ha.
Meecha Ajụjụ Ule Ọmarịcha
Ị chọrọ ime ajụjụ ule ọmarịcha gbasara Energetics? Budata ngwa Green Bridge CBT iji nweta ajụjụ ule ọmarịcha na nyocha zuru ezu gbasara isiokwu a.
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Ihe nile ichoro iji nwee ihe ịga nke ọma na JAMB, WAEC & NECO.
