A 10.0-mL sample of aqueous HCl requires 30 mL of 0.05 M NaOH to reach the endpoint. What is the molar concentration of HCl?

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

Define dew point. i am writing this part to be able to ask the question

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.