Given that h(g) h(g) → h2(g) ∆h°= -436. 4 kj/mol calculate the change in mass (in kg) per mole of h2 formed.

What does the cell nucleus do or, how does it function?

How do you identify the anode on a power source such as a battery? how do you identify the cathode? how are terms anion and cation?

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.)