A chemist adds two substances together in a beaker. When he combines the substances, a solid substance is formed. He filters the solid substance and measures its mass on an electronic balance. When the chemist measures the mass of the substance, he is A. collecting relevant data. B. devising a hypothesis. C. making a prediction. D. drawing a conclusion.

Calculate the molarity of 48.0 ml of 6.00 m h2so4 diluted to 0.250 l .

What overall charge must all compounds have

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.)