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Moles to Moles

1. Record and calculate the following:

(a) Mass of copper used in the reaction (g) 114.815g

(b) Moles of copper used in the reaction (a simple stoichiometric conversion of mass to moles using the molar mass for copper of 63.5 g/mol. Show your work).

(b) Mass of beaker and dry silver (g) 313.867

(c) Mass of an empty beaker (g) 111.420 g

(d) Mass of silver produced by the reaction (g) 316.262 g silver and beaker

(e) Moles of silver produced by the reaction (also a one-step stoichiometric conversion from mass of silver, to moles; using the molar mass of Ag as 107.9 g/mol)

(f) Now, compare the ratio of moles of copper reacted to the moles of silver produced. (Simply determine which molar amount from calculations b. and e. is largest, and divide the smallest value by the largest value. This will give you the molar ratio-hopefully a whole number-between copper reacted and silver produced.)

2. Write the balanced equation for the reaction between solid copper and silver nitrate, that produces solid silver and copper(II) nitrate in solution. Include your experimentally determined mole ratios for the copper and silver atoms as coefficients.

3. If the silver in the beaker contained water during your last weighing, how would this affect your results?

4. Assume that magnesium would act atom-for-atom exactly the same as copper in this experiment. How many grams of magnesium would, have been used in the reaction if one gram of silver were produced? The atomic mass of magnesium is 24.31 g/mol.

5. Explain the source of the blue color of the solution after the reaction. Why was the blue color not apparent in the original solution of AgNO3?

317.262 if Cu and silver turn blue from clear

Solution Preview

Record and calculate the following:

(a) Mass of copper used in the reaction (g) 114.815g

(b) Moles of copper used in the reaction (a simple stoichiometric conversion of mass to moles using the molar mass for copper of 63.5 g/mol. Show your work).
Number of moles = 114.815/63.5 = 1.808 moles

(b) Mass of beaker and dry silver (g) 313.867

(c) Mass of an empty beaker (g) 111.420 g

(d) Mass of silver produced by the reaction (g) 316.262 g silver and beaker

(e) Moles of silver produced by the reaction (also a one-step stoichiometric conversion from mass of silver, to moles; using the molar mass of Ag as 107.9 g/mol)
Mass of dry silver = 313.867 g - 111.42 g = 202.447 g

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