UHS MDCAT 2025 Chemistryuhs mdcat chemistry 2025#Atomic Structure#Planck's Constant1361Choose the best answerThe value of Planck's constant is:A6.626 × 10⁻³⁰ J·secB6.626 × 10⁻³² J·secC6.626 × 10⁻³⁴ J·secD6.626 × 10⁻³⁶ J·sec Like 0 Discuss 0Share
Chemical KineticsRate Law from Reaction Mechanism1362Choose the best answerConsider the mechanism: Step 1: 2NO ⇌ N₂O₂ (fast equilibrium) Step 2: N₂O₂ + H₂ → N₂O + H₂O (slow) Step 3: N₂O + H₂ → N₂ + H₂O (fast) The overall rate law is:ARate = k[NO]²[H₂]BRate = k[N₂O₂][H₂]CRate = k[NO]²DRate = k[N₂O₂][H₂]² Like 0 Discuss 0Share
Stoichiometry 11#Atomic Mass Conversion1363Choose the best answerWhat is the approximate mass of one ²³Na atom in kilograms?A3.82 × 10⁻²⁶ kgB2.30 × 10⁻²⁶ kgC1.66 × 10⁻²⁷ kgD3.82 × 10⁻²³ kg Like 0 Discuss 0Share
Stoichiometry Stoichiometry MCQS#Chemical Changes1364Choose the best answerWhich observation is the strongest evidence that a chemical reaction has occurred?AA substance changes its shapeBA new gas is formed during the reactionCA solid is broken into smaller piecesDSugar dissolves in water Like 0 Discuss 0Share
LiquidsDipole–Dipole Forces1365Choose the best answerAttraction between the partially positive end of one polar molecule and the partially negative end of another is called:ADipole–dipole attractionBLondon dispersion forceCIon–dipole attractionDCovalent bonding Like 0 Discuss 0Share