What is the molarity of a HCL solution if the reaction of 45.2 mL of a HCl solution with excess magnesium produces 5.20 L of H2 gas at 735 mmHg and 25 degrees Celsius?

Iknow #2 is d. i just need to know why

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

When the speed of the bottle is 2 m/s, the average maximum height of the beanbag is m.