Using the chemical stoichiometry, determine the number of moles of carbonic acid that can be produced from 4 mol of nahco3 and 8 mol hci

The table lists pressure and volume values for a particular gas. which is the best estimate for the value of v at p = 7.0 × 103 pascals?

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.)

What does the xylem do? stores the glucose captures the sunlight absorbs oxygen into the leaf carries water from the roots to the leaves