How many grams of potassium carbonate are needed to make 2. 00×102 mL (200 mL) of a 2. 5 M solution? Enter the answer with the appropriate number of significant figures.

If 10.g of agno3 is available, what volume of 0.25 m agno3 can be prepared

Describe the interaction that occurs between two objects with the same electrical charge.

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.)