CHEMISTRY ACS EXAM (1ST SEMESTER) WITH CORRECT QUESTIONS AND ANSWER.

CHEMISTRY ACS EXAM (1ST SEMESTER) WITH CORRECT QUESTIONS AND ANSWER. Ion - ️️# electrons doesn't equal # protons Isotope - ️️Each isotope has different # of neutrons Isotopic - ️️same # of neutrons Transition Metal Orbitals - ️️The 4s orbital is filled before the 3d orbital, but listed after. Paramagnetic - ️️Atoms that possess a permanent magnetic charge due to the presence of unpaired electrons. Electropositive - ️️Tending to lose electrons and form positive ions Resonance Structures - ️️Two equally correct arrangements of one molecule's electrons; generally the molecule exists as an average of the two. Polar Molecule - ️️mostly positive on one side and mostly negative on the other Free Radicals - ️️Compounds with an odd number of electrons in their Lewis Structure. Eg. NO₂ Incomplete Octets - ️️Occur in elements that can form stable bonds with less than eight electrons. Eg. BF₃ Expanded Octets - ️️Occur in the third row of the periodic table and beyond in elements that can form stable bonds with more than eight electrons. Eg. XeF₂ Hydrogen Bonding - ️️When hydrogen is attracted to electronegative atoms. Silicon Dioxide - ️️Has a unique structure; O-Si-O bonds are always 109.5°. Formal charge - ️️V - N - (B/2) where V = total valence e⁻, N = non-bonding e⁻, and B = bonding e⁻. Isomer - ️️Two molecules that are composed of the same type and number of elements but are arranged in different ways and have different properties are isomers. Molar Volume - ️️(Vm) The volume occupied by one mole of a substance. Molar Volume of an Ideal Gas - ️️22.414 L/mol @ STP Limiting Reagent - ️️The component of a chemical reaction that will be completely used up first. Atomic Mass - ️️Can be g/mol, kg/kmol, mg/mmol, etc. Specific Heat - ️️The amount of heat required to raise the temperature of one gram of a substance by one °C. (units: J x g⁻¹ x °C⁻¹) Heat (J) - ️️mass (g) x specific heat (J x g⁻¹ x °C⁻¹) x ΔT (°C) Molar Heat Capacity - ️️Same as specific heat, but requirement for raising 1 mole of a substance by one °C. Bond Energy - ️️The energy required to break a bond, and the energy released when a bond is formed. Bomb Calorimeter - ️️An insulated container used to study reactions at a constant volume. Calorimeter Constant - ️️Amount of energy required to raise the water surrounding the chamber of the bomb calorimeter by one °C Gibbs Free Energy - ️️ΔG = ΔH - TΔS, where ΔH = change in enthalpy and ΔS = change in entropy. Enthalpy - ️️change in energy of a system. Entropy - ️️change in chaos of a system. Free Energy - ️️change in spontaneity of a system. Boiling Point - ️️The point at which the vapor pressure of a liquid equals 1 atm. Normal Melting Point - ️️The temperature at which the solid and liquid phases of a substance are in equilibrium at atmospheric pressure (760 mm Hg). Graham's Law of Effusion - ️️The lighter a gas's atomic weight, the faster it will escape a container. Molarity - ️️mols/L; mmols/mL