Balance Reactions: Zn + 2AgNO3 -> 2Ag + Zn(NO3)2

[staceybeth]

2.00 g of zinc metal
2.50 g of silver nitrate

Zn + 2 AgNO3----->2Ag + Zn(NO3)2

A) how many grams of the excess reactant will be left at the end of the reaction?

 

[Borek]

You just don't ask. You try, you tell us what you did, we push you in the right direction.

Limiting reagent calculations.

 

[Blueshift5]

To determine the grams of excess reactant, we first need to calculate the limiting reactant. This is done by comparing the number of moles of each reactant to the stoichiometric ratio in the balanced equation. In this case, the moles of zinc (Zn) can be calculated by dividing its mass (2.00 g) by its molar mass (65.38 g/mol). This gives us 0.0306 moles of Zn. Similarly, the moles of silver nitrate (AgNO3) can be calculated by dividing its mass (2.50 g) by its molar mass (169.87 g/mol), giving us 0.0147 moles of AgNO3.

From the balanced equation, we can see that for every 1 mole of Zn, we need 2 moles of AgNO3. Therefore, 0.0306 moles of Zn will require 0.0306 x 2 = 0.0612 moles of AgNO3. However, we only have 0.0147 moles of AgNO3, which means it is the limiting reactant. This also tells us that Zn is in excess.

To determine the grams of excess reactant, we can use the number of moles of AgNO3 (0.0147 moles) and its molar mass (169.87 g/mol) to calculate its mass. This gives us 2.50 g of AgNO3. Therefore, at the end of the reaction, there will be 2.50 g of excess AgNO3 left.

B) What is the theoretical yield of silver in grams?

To determine the theoretical yield of silver, we need to calculate the moles of silver (Ag) produced in the reaction. From the balanced equation, we can see that for every 2 moles of Ag, we need 1 mole of Zn. Therefore, the moles of Ag produced will be half of the moles of Zn used. This means that 0.0306 moles of Ag will be produced.

To calculate the theoretical yield of Ag in grams, we can use its molar mass (107.87 g/mol) and the number of moles (0.0306 moles). This gives us a theoretical yield of 3.30 g of Ag.

C) What is the percent yield