Susan ran a marathon (26.2 miles) in 6.5 hours. what was susan's average speed?

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.

1.17 mol hcl and 2.5 mol naoh react according to the equation hcl + naoh -> nacl + h2o . if the limiting reactant is hcl, determine the amount of excess reactant that remains. answer in units of mol.

If the solubility of a gas in water is 1.22g/2.75 atm, what is it’s solubility (in g/l) at 1.0 atm