Atomic Structure
This subatomic particle has no charge and is found in the nucleus
What is a neutron?
This is the ratio of coefficients used to relate substances in a balanced chemical equation.
What is the mole ratio?
This quantity represents heat flow at constant pressure.
What is enthalpy (ΔH)
This is the state when forward and reverse reaction rates are equal.
What is equilibrium?
This scale measures acidity and ranges from 0 to 14
What is the pH scale?
This number represents the total number of protons in an atom
What is the atomic number?
This is the limiting reactant in a reaction where 2 mol H₂ reacts with 1 mol O₂
This sign of ΔH indicates an exothermic reaction.
What is negative?
This principle predicts how a system at equilibrium responds to stress
What is Le Châtelier’s Principle?
This ion determines if a solution is acidic.
What is H⁺ (or H₃O⁺)?
This model describes electrons as existing in probability clouds rather than fixed orbits
What is the quantum mechanical model?
This is the number of moles in 44 grams of CO2
What is 1 mole?
This law states that energy cannot be created or destroyed.
What is the First Law of Thermodynamics?
If Q < K, the reaction will shift in this direction.
What is toward products?
This is the pH of a neutral solution at 25°C.
What is 7?
This rule states that no two electrons in an atom can have the same set of four quantum numbers
What is Pauli exclusion principle?
This is the theoretical yield if 5 mol of reactant produces product in a 1:1 ratio
What is 5 moles?
If ΔH is negative and ΔS is negative, this condition makes the reaction spontaneous
What is low temperature?
This happens to equilibrium if pressure increases in a reaction with fewer moles of gas on one side.”
What is it shifts toward that side?
This happens to pH when a strong base is added to a solution.
What is it increases?
This element has an electron configuration ending in 3p⁴ and forms a -2 ion. Identify the element and explain why it forms that charge.
What is sulfur?
Sulfur has 6 valence electrons and gains 2 to achieve a full octet, forming S²
When 10.0 g of CaCO₃ decomposes completely, this mass of CO₂ is produced.
What is approximately 4.4 g CO₂?
CaCO₃ → CaO + CO₂
Molar mass CaCO₃ ≈ 100 g/mol → 10 g = 0.10 mol → produces 0.10 mol CO₂ → 0.10 × 44 g/mol = 4.4 g
A reaction has ΔH = +75 kJ and ΔS = +100 J/K. Determine the temperature above which the reaction becomes spontaneous.
What is 750 K?
ΔG = ΔH – TΔS = 0 → T = ΔH / ΔS
Convert ΔS: 100 J/K = 0.100 kJ/K
T = 75 / 0.100 = 750 K
For the reaction N₂ + 3H₂ ⇌ 2NH₃, if the equilibrium constant K is very large, this describes the position of equilibrium and relative concentrations
What is equilibrium strongly favors products, with mostly NH₃ present?
A solution has a pH of 3. Calculate the hydronium ion concentration and determine how many times more acidic it is than a solution with pH 6.
What is [H₃O⁺] = 1 × 10⁻³ M and it is 1000 times more acidic?
pH = –log[H₃O⁺] → 10⁻³ vs 10⁻⁶ → difference of 10³ = 1000×