1. Iron (II) in aqueous solution can be quantitated by an oxidation-reduction process using dichromate, Cr2O72-: Cr2O72-(aq) 6 Fe2 (aq) 14 H (aq) 2 Cr3 (aq) 6 Fe3 (aq) 7 H2O(l) Write the balanced half-reactions for the oxidation of iron (II) and the reduction of dichromate.

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

Displacement is the slope of a velocity vs. time graph a. true b. false

Correct relationship between molecular formula and empirical formula