How many liters of nitrogen dioxide gas are produced when 84.9 grams water reacts with nitrogen dioxide?

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.)

Take a look at this dandelion. the yellow flower on the right is pollinated and the seeds on the left are transported by

Calculate the ph of a .10m nh4cl solution. the kb value for nh3 is 1.8×10^-5