The solubility of cr(no3)3⋅9h2o in water is 208 g per 100 g of water at 15 ∘c. a solution of cr(no3)3⋅9h2o in water at 35 ∘c is formed by dissolving 310 g in 100 g water. when this solution is slowly cooled to 15 ∘c, no precipitate forms. at equilibrium, what mass of crystals do you expect to form?

What’s the percent by mass of carbon in c10h14n2

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 are some natural measures of time