Use the information and picture to answer the following question. A student prepares two solutions as shown. The dots represent solute particles. The student wants to test the conductivity of each solution. Prior to carrying out the investigation, the student needs to identify the variables being controlled and the variables being changed between the two solutions. Which identification of the variables is correct?

Calculate the mass of silver needed to react with chlorine to produce 126g if silver chloride?

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 does concentration affect reaction rate