Write a balanced chemical equation for each of the following double-replacement reactions. a. A water solution of zinc bromide (ZnBr) and a water solution of potassium hydroxide form a water solution
of potassium bromide and a precipitate of zinc hydroxide.
b. A water solution of copper(II) sulfate and a water solution of barium chloride produce a water solution of
copper(ll) chloride and solid barium sulfate.
C. A precipitate of iron(III) carbonate and a water solution of sodium nitrate are formed when a water solution
of iron(III) nitrate and a water solution of sodium carbonate are mixed.

Which of the following statements is not true? • a. covalent compounds have low melting and boiling points. • ob. covalent bonds between atoms of a compound are relatively weak compared to bonds between molecules. • c. covalent bonds occur between nonmetals. • d. covalent compounds are often gases or liquids.

Use this information to determine the number of calends electrons in the atoms. which of the following correctly compares the stability of the two atoms? a) both are unreactive b) both are highly reactive c) a is unreactive and d is reactive d) a is reactive and d is unreactive

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.)