Students use a 2.5 M solution of diluted hydrochloric acid. The Molarity of the solution they end up with is .125 M. and had a volume of 5500mL. What volume of the concentrated HCl did they begin with?

Will mark brainliest 26. which of these statements are true? (3 points) a. gases are compressible b. gases fill their containers completely c. the pressure of a gas is independent of the temperature d. gases have mass e. gases exert pressure f. the pressure of a gas is dependent on the volume g. gas pressure results from the collisions between gas particles h. gases have a definite volume and shape

Which characteristics can be used to differentiate star systems? check all that apply.

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)