Please help me complete #8 #9 and #10

Alculate the concentration of h3o⁺in a solution that contains 5.5 × 10-5m oh⁻at 25°c. identify the solution as acidic, basic, or neutral. a) 1.8 × 10-10m, basicb) 1.8 × 10-10m, acidicc) 5.5 × 10-10m, neutrald) 9.2 × 10-1m, acidice) 9.2 × 10-1m, basic

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.

May someone me with these science questions