The thermal decomposition of phosphine (PH3) into phosphorus and molecular hydrogen is a first-order reaction: 4PH3(g) P4(g) 1 6H2(g) The half-life of the reaction is 35.0 s at 6808C. Calculate (a) the first-order rate constant for the reaction and (b) the time required for 95 percent of the phosphine to decompose.
CH. 1: MATTER AND ENERGY 1.1: States of Matter Matter: object that has mass (m) and occupies space Chemistry: study of the composition, structure, and properties of matter Solid→ definite volume and shape ● May vibrate ● Compact ● Stationary ● Can’t move past other molecules Liquid→ definite volume, but OT a definite shape ● Can flow past each other Gas (vapor) → NO definite volume and NO definite shape ● Separated ● Mostly empty space ❖ Matter can be transformed from one physical state to another as its temp goes up or down Atom: smallest particle of an element Molecules: 2+ atoms of same element Ex) H2 Chemical bonds: force that holds 2 atoms in a molecule or compound together Melting: solid→ liquid Ex) Ice tur
