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
Maelezo ya Somo
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Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.
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
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Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.
Inapatikana kwenye programu ya Green Bridge
Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.
Vitabu Vinavyopendekezwa
Fanya Mazoezi ya Maswali ya Majaribio
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