Energetics
Muhtasari
When chemicals react, energy is exchanged with the surroundings. Some reactions release heat and warm everything around them; others absorb heat and make the surroundings cooler. Understanding which direction the energy flows, and how to measure it, is at the heart of energetics.
In this lesson you will distinguish exothermic from endothermic reactions, carry out calorimetry calculations using Q = mcDeltaT, work out molar enthalpy changes, and interpret energy level diagrams. These skills appear regularly on both Paper 1 and Paper 2 of the Edexcel Science Double Award.
Malengo
- Know that chemical reactions in which heat energy is given out are exothermic and those in which heat energy is taken in are 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 Q = mcDeltaT
- Calculate the molar enthalpy change from the heat energy change Q
- Investigate temperature changes accompanying various types of change
Ramani ya mawazo
Mada hii imechorwa ili uone jinsi mawazo yanavyounganika.
Fungua ramani ya mawazo kwenye programu
Kadi za kumbukumbu
Mazoezi ya haraka ya kumbukumbu kuhusu kinachopimwa katika mada hii.
Fanya mazoezi ya kadi hizi kwenye programu
Maelezo ya Somo
Dokezo Kamili la Somo Linapatikana kwenye Programu ya Green Bridge
Pata programu ya Green Bridge CBT kwenye simu au kompyuta yako kwa maktaba kamili ya IGCSE: mitihani ya miaka iliyopita, miongozo ya usahihishaji, ramani za mawazo, kadi za marudio na masomo ya sauti.
Tathmini ya Somo
Hongera kwa kukamilisha somo la Energetics. Sasa kwa kuwa umechunguza dhana na mawazo muhimu, ni wakati wa kuweka ujuzi wako kwa mtihani. Sehemu hii inatoa mazoezi mbalimbali maswali yaliyoundwa ili kuimarisha uelewaji wako na kukusaidia kupima ufahamu wako wa nyenzo.
Utakutana na mchanganyiko wa aina mbalimbali za maswali, ikiwemo maswali ya kuchagua jibu sahihi, maswali ya majibu mafupi, na maswali ya insha. Kila swali limebuniwa kwa umakini ili kupima vipengele tofauti vya maarifa yako na ujuzi wa kufikiri kwa makini.
Tumia sehemu hii ya tathmini kama fursa ya kuimarisha uelewa wako wa mada na kubaini maeneo yoyote ambapo unaweza kuhitaji kusoma zaidi. Usikatishwe tamaa na changamoto zozote utakazokutana nazo; badala yake, zitazame kama fursa za kukua na kuboresha.
- Which of the following reactions is endothermic? A) Combustion of methane B) Neutralisation of an acid C) Thermal decomposition of calcium carbonate D) Displacement of copper by iron Answer: C
- In the equation Q = mcDeltaT, what does c represent? A) Concentration B) Specific heat capacity C) Number of moles D) Temperature change Answer: B
- On an energy level diagram for an exothermic reaction, the products are: A) At a higher energy level than the reactants B) At the same energy level as the reactants C) At a lower energy level than the reactants D) Not shown on the diagram Answer: C
- A calorimetry experiment uses 100 cm3 of water. The mass of water used in the calculation is: A) 0.1 g B) 10 g C) 100 g D) 1000 g Answer: C
- What is the activation energy of a reaction? A) The total energy released by the products B) The minimum energy needed to start the reaction C) The difference between reactant and product energy D) The heat energy absorbed from the surroundings Answer: B
Fanyia kazi maswali haya kwenye programu
Fanyia kazi maswali haya kwenye programu
Vitabu Vinavyopendekezwa
Jifunze zaidi kutoka vyanzo huria
-
Sehemu ya kitabu
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
-
Sehemu ya kitabu
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
Vimechapishwa na mashirika mengine chini ya leseni huria na vinatajwa kama wanavyoomba. Viungo hufungua tovuti zao.
Fanya Mazoezi ya Maswali ya Majaribio
Ungependa kufanya mazoezi ya maswali ya majaribio kuhusu Energetics? Pakua programu ya Green Bridge CBT ili kupata maswali ya majaribio na tathmini kamili za mazoezi kuhusu mada hii.
Pakua Programu Kwenye Google Playstore
Kila kitu unachohitaji ili kufaulu katika JAMB, WAEC & NECO.
