Enthalpy Study guides, Class notes & Summaries

Detailed notes on Unit 8 - Energetics I covering all the specification points, and allowed me to achieve an A* in chemistry. Covers enthalpy changes, thermochemical equations, Hess's law, Hess cycles, example calculations, standard enthalpy of formation, reaction, combustion, neutralisation and atomisation, bond enthalpy calculations with examples and enthalpy titrations.

CHEM 210 MODULE 3 EXAM QUESTIONS AND CORRECT ANSWERS, WITH COMPLETE SOLUTION 2024. What is meant by the term average bond enthalpy? (Average enthalpy change) when one mole of bonds of (gaseous covalent) bonds is broken The calculated value of ΔHc from this experiment is different from the value obtained from data books. Apart from heat loss, suggest two reasons for the difference. Assume that the calculation has been carried out correctly. incomplete combustion non-standard conditi...

AQA CHEMISTRY A LEVEL WITH COMPLETE SOLUTIONS covalent bond - ANSWER-a shared pair of electrons between non-metal elements co-ordinate bond - ANSWER-a shared pair of electrons where both electrons are supplied by one atom repulsion in shapes of molecules - ANSWER-Lone pair-lone pair > lone pair-bonding pair > bonding pair-bonding pair electronegativity - ANSWER-the power of an atom to attract the pair of electrons in a covalent bond hess' law - ANSWER-Total enthalpy chang...

CEM 142 EXAM 2 LATEST UPDATE GRADED A+ **ACID = ELECTRON PAIR ACCEPTOR Acid= electrophile **BASE = ELECTRON PAIR DONOR base= nucleophile strong acid fully ionizes in solution/completely dissociates weak acid does not fully ionize or dissociate into ions ** negatively charged ion ---> wants to loose 1 electron can tell if a solution is ionized when... a fully ionized solution will conduct more electricity than a non fully ionized solution strength of acid depend...

A __________ ΔH corresponds to an __________ process. -zero, endothermic -positive, exothermic -negative, endothermic -zero, exothermic -positive, endothermic correct answerspositive, endothermic Which one of the following is NOT considered a fossil fuel? -natural gas -hydrogen -anthracite coal -petroleum -crude oil correct answershydrogen Which one of the following statements is FALSE? -The enthalpy change for a reaction is equal in magnitude, but opposite in si...

AQA A-Level Chemistry Exam (2024) || All Questions & Answers (Graded A+) AQA A-Level Chemistry Exam (2024) || All Questions & Answers (Graded A+) Topic 1 - ANSWER - Atomic Structure Topic 2 - ANSWER - Amount of Substance State what is meant by the term molecular formula. - ANSWER - the actual no. atoms of each element in a compound Topic 3 - ANSWER - Bonding Explain why CF4 has a bond angle of 109.5°. - ANSWER - -there are 4 bonding pairs and no lone pairs -repel equally and th...

Lattice energy - - The enthalpy change when 1 mole of ionic compound is formed from its gaseous ions under standard conditions - It is the energy given out when ions of opposite charges comes together to form an ionic lattice Lattice energy is endothermic or exothermic? - - It is always exothermic because bonds are being formed (ionic bond) between oppositely charged ions, not broken Equation showing the formation of NaCl lattice - - Na^+(g) + Cl^-(g) > NaCl(s) The state of the opposite...

Biology 1201 LSU Exam 2 Questions and Answers 100% Pass What type of chemical reaction is without outside energy? Spontaneous (exergonic/downhill) NOT INSTANTANEOUS -decreasing enthalpy and increasing entropy What is the equation for Free Energy? deltaG=deltaH-TdeltaS -free enrgy=enthalpy-(temp.)(entropy;disorder) -high deltaS=low delta G Entropy Disorder: -breakdown: increase in disorder, more parts -synthesis: decrease in disorder, less parts -high entropy=low free energy ...

temperature is related to KE how? temp is the average kinetic energy thermal energy is related to KE how? thermal energy is the total KE Brainpower enthalpy of fusion is ALWAYS greater than enthalpy of vaporization because? it has to break more bonds (solid --> liquid) the amount of heat depends on (2 factors) 1. the type of substance 2. the amount of the substance during a phase change does temperature change? NO if an archaebacerial species lives in a pool that is 0.01 M HCL wh...

elative atomic mass (Ar) : Average mass of an atom compared with one twelth of the mass of an atom of carbon 12 Electronegativity : Power of an atom to attract the pair of electrons in a covalent bond Standard enthalpy of combustion : Enthalpy change when 1 mole of a substance burns completely in oxygen under standard conditions with all reactants and products being in their standard state Standard enthalpy of formation : Enthalpy change when 1 mole of a compound is formed from it's ...