Bond enthalpies - Study guides, Class notes & Summaries

Endothermic reaction - correct answer To break bonds, the surroundings need to give energy to the molecule. The bonds gains energy, as they take in energy so have a positive sign. The system loses energy so gets colder Exothermic reaction - correct answer To make bonds, the molecule give energy to the surroundings. The bonds lose energy, as they give out energy so have a negative sign. The system gains...

General Chemistry ACS EXAM (2015 version) 60 Questions with Verified Answers A 20.0 g sample of mercury(II) oxide (HgO, M = 216.6) is heated strongly, causing it to decompose to metallic Hg and O2 gas. What volume of O2 gas is produced (measured at STP)? (A) 1.03 L (B) 2.07 L (C) 4.14 L (D) 14.0 L - CORRECT ANSWER A When 30.0 mL of 0.10 M AgNO3 is added to 30.0 mL of 0.10 M NaCl, aqueous NaNO3 and solid AgCl are formed. How much solid AgCl is produced? (A) 0.0030 mol (B) 0.0...

Matter Most basic building block. Must have mass and volume Elements Simplest form of matter, can't decompose any further Molecules Two or more atoms "linked" together Compounds Mixes of two or more elements bonded together Sig Fig.- x & / As many as the least number Sig Fig.- + & - As many as the least behind the decimal point Law of Definite Composition Components in a compound always have the same ratio by mass Law of Multiple Proportions Ratios of elements that combine to m...

Answer all the questions. 1 Which statement describes electronegativity? A A measure of the reactivity of an element. B The ability of an atom to attract an electron to become a 1– ion. C The attraction of a bonded atom for the electrons in a covalent bond. D The attraction of an atom for a lone pair of electrons. Your answer [1] 2 A chlorate(VII) ion has a 1– charge. What is the formula for sodium chlorate(VII)? A NaCl O3 B NaCl O4 C NaCl O7 D NaCl O8 ...

MCAT Exam Practice Questions With Answers Latest Updated 2024 (100% Verified) Thin layer chromatography can use silica plates which are very polar. Will polar or non polar substances have lower Rf values on this plate? Polar substances - they will have a higher affinity for the silica and thus will not travel as far as the non polar substances A titration of a strong acid with a strong base or vice versa has an equivalence point around what pH? 7 What type of bond is usually disrupted duri...

Thin layer chromatography can use silica plates which are very polar. Will polar or non polar substances have lower Rf values on this plate? Polar substances - they will have a higher affinity for the silica and thus will not travel as far as the non polar substances A titration of a strong acid with a strong base or vice versa has an equivalence point around what pH? 7 Brainpower Read More 0:06 / 0:15 What type of bond is usually disrupted during denaturation of proteins? ...

Standard enthalpy of formation correct answer: enthalpy change when it is made from the stable form of its elements at standard condition combustion enthalpy correct answer: exothermic, so always negative atomisation enthalpy correct answer: endothermic, so always positive ∆H(rxn)= correct answer: ∑∆Hºf(products) - ∑∆Hºf(reactants) standard enthalpy of formation correct answer: change of enthalpy during the formation of one mole of the substance from its constituent ...

AP CHEM FINAL EXAM | Complete Updated Answered Solution guide 2023. 6.1 For a classroom demonstration, a chemistry teacher puts samples of two different pure solid powders in a beaker. The teacher places the beaker on a small wooden board with a wet surface, then stirs the contents of the beaker. After a short time the students observe that the bottom of the beaker is frozen to the wood surface. The teacher asks the students to make a claim about the observation and to justify their claims. W...

Thin layer chromatography can use silica plates which are very polar. Will polar or non polar substances have lower Rf values on this plate? - ANSWER-Polar substances - they will have a higher affinity for the silica and thus will not travel as far as the non polar substances A titration of a strong acid with a strong base or vice versa has an equivalence point around what pH? - ANSWER-7 What type of bond is usually disrupted during denaturation of proteins? - ANSWER-H bond Is uracil a ...

OCR CHEMISTRY A H032 LATEST UPDATED FINAL 2024 QUESTIONS AND VALID ANSWERS LATEST UPDATE//ALREADY GRADED A+ Describe how HCl is removed from the waste gases produced - ANSWER - HCl gas is passed through alkali (carbonate) what do the experi mental results tell you about the carbon -halogen bond enthalpies - ANSWER - bond enthalpy decreases down group 7 c - cl>c - br>c - i How could the student modify their experiment so that...