Atomic Structure & Periodicity
This is the number of protons, neutrons, and electrons in a neutral atom of uranium-238.
What are 92 protons, 146 neutrons, and 92 electrons?
This is the molecular geometry and bond angle of SF₆.
What is octahedral with 90° bond angles?
This is the limiting reagent when 3.0 mol of Al reacts with 4.0 mol of Cl₂ to form AlCl₃.
What is Cl₂?
This is the definition of the standard enthalpy change of formation.
What is the enthalpy change when 1 mole of a compound is formed from its elements in their standard states under standard conditions?
This is how a Brønsted–Lowry acid and base are defined.
What is a proton donor and a proton acceptor?
This term describes the minimum energy required to remove an electron from an atom or ion in its gaseous state.
What is the first ionization energy?
This is why MgO has a significantly higher melting point than NaCl.
What is the presence of higher charges in MgO resulting in stronger ionic bonding?
This is the empirical formula of a compound composed of 40.0% C, 6.7% H, and 53.3% O.
What is CH₂O?
This is what an exothermic reaction implies about its bond strengths.
What is the bonds formed are stronger than the bonds broken?
This is the pH at the equivalence point of a titration between a weak acid and a strong base.
What is greater than 7?
This is the explanation for why the atomic radius of chlorine is smaller than that of sulfur.
What is a higher nuclear charge in chlorine that pulls electrons closer?
This type of hybridization is used by the central atom in ethene (C₂H₄).
What is sp² hybridization?
This is the volume of hydrogen gas produced at STP when 2.00 g of calcium reacts with excess water.
What is 1.13 liters?
This is the enthalpy change for the complete combustion of methane using average bond enthalpies:
C–H = 412, O=O = 498, C=O = 805, O–H = 463.
What is –818 kJ/mol?
This is the conjugate base of H₂PO₄⁻.
What is HPO₄²⁻?
This is the maximum number of electrons that can occupy the third energy level of an atom.
What is 18 electrons?
This explains why graphite conducts electricity while diamond does not.
What is the presence of delocalized electrons in graphite but only localized electrons in diamond?
This is the actual yield if the theoretical yield of a reaction is 10.2 g and the percent yield is 78.4%.
What is 7.998 g?
This is the value of ΔG for a reaction at 298K where
ΔH = –150 kJ/mol and ΔS = –200 J/mol·K.
What is –90.0 kJ?
This is the pH of a 0.010 mol/L HNO₃ solution.
What is 2.00?