In a chemical reaction between copper metal and silver nitrate, 12.7 g of copper(II) and 64.5 g of silver nitrate react, and 38.1 g of Silver is produced. 21) Predict the products and write the balanced equation and include the physical state of each. 22) What type of chemical reaction is this? 23) Which is the limiting reactant? You must include the work for this to receive full credit. 24) What mass of excess is used up, and what mass is left over? 25) Calculate the percent yield.

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.)

If oil spills continue, all of the following should be expected except (2 points) death of aquatic life. polluted groundwater. decreased soil productivity. increased global temperatures.

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