Enthalpy change - Study guides, Class notes & Summaries

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...

10th Grade Honors Chemistry Final Exam Questions And Answers Well Illustrated 2024. Thermochemistry - correct answer. The study of heat effects in chemical reactions. Exothermic Reaction - correct answer. A reaction that releases energy in the form of heat. Examples: Combustion, freezing water. Heat generated is added to the product side (right side) because heat is released. Endothermic Reaction - correct answer. A reaction that absorbs energy in the form of heat. ...

CEM 142 First Exam Latest Update Already Passed Define and give examples of open, closed and isolated systems Open system-both matter and energy can enter or leave (beaker without a lid, pour your hot drink into a mug) Closed system- the amount of matter is constant and only energy can enter or leave (cup of coffee with a lid on it) Isolated systems- neither energy nor matter would move between the system and the surroundings (Styrofoam coffee cup with a lid on) Explain the dif...

What is the third law of thermodynamics? Correct Answer The entropy of a perfect crystal is zero. What is the second law of thermodynamics? Correct Answer As a whole, the universe always tends towards increasing entropy. What is the relationship between number of microstates and entropy? Correct Answer More microstates = higher entropy What is the relationship between temperature and entropy? Correct Answer Temperature increases, entropy increases (direct) What is the relationship be...

10th Grade Honors Chemistry Final Exam Flashcards Thermochemistry ️The study of heat effects in chemical reactions. Exothermic Reaction ️A reaction that releases energy in the form of heat. Examples: Combustion, freezing water. Heat generated is added to the product side (right side) because heat is released. Endothermic Reaction ️A reaction that absorbs energy in the form of heat. Examples: Melting ice, evaporating liquid water, boiling water. Heat generated is added to the ...

Relative atomic mass : The average mass of an atom of an element, relative to 1/12th of the mass of an atom of Carbon-12 Relative molecular mass : Average mass of a molecule compared to 1/12th of the mass of a carbon-12 atom The Avogradro constant : the number of particles in a mole ideal gas equation : pV = nRT empirical formula : the simplest whole number ratio of atoms of each element in a compound 2 percentage atom economy : (Mass of desired product/total mass of reactants) x 1...

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

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...

Lattice enthalpy The enthalpy change when one mole of an ionic compound is converted to gaseous ions. Enthalpy of atomisation The enthalpy change when one mole of gaseous atoms isformed from the element in its standard state. First electronaffinity The enthalpy change when one mole of gaseous atoms is converted into gaseous ions with a single negative charge. Enthalpy of solution The enthalpy change when one mole of a solute dissolves in water. Enthalpy of hydra...

Phase - Answer-Substance in a form of matter which is homogeneous throughout in chemical composition and physical state Transition - Answer-A change from one state to another at a characteristic temperature and a given pressure What happens to free energy between phase in a spontaneous process? - Answer-The free energy decreases between phases What happens to free energy as the pressure increases? - Answer-Free energy increases as pressure increases due to the fact that molar volume is al...