Which of the following is a conjugate acid/base pair? 1) H₃PO₄ and PO₄³⁻
2) H₂PO₄- and PO₄³⁻
3) HPO₄²⁻ and PO₄³⁻
4) H₃PO₄ and HPO₄²⁻

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.)

How is the shape of the poem “peer” connected to its meaning?

How does climate change cause the ocean's thermohaline current to slow down?