I'm not sure how to do or show the work for these two questions. A) & B.)!! please anyone help:
A.) Suppose a chemical reaction starts with 5.00 g of copper (i) nitrate and 2.00 g of magnesium chloride.
Balanced Equation:
2 CuNo3 + MgCl2 ---> 2 CuCl + MgNO3
1.) determine the identity and mass of the excess reactant.
2.) Determine the identity of the limiting reactant.
3.) Determine the mass of each product that can be produced.
4.) Calculate the percent yield of copper (i) chloride if 3.50 g of copper (i) chloride is actually collected.
___________________________________
B.) Suppose a chemical reaction starts with 15.0 g of sodium nitrate and 13.1 g of potassium sulfate.
1.) determine the identity & mass of excess reactant.
2.) Determine identity of limiting reactant
3.) Determine mass of each product that can be produced.
4.) Calculate percent yiled of potassium nitrate if 11.9 g of potassium nitrate is actually collected.
#2 is easy. There is no reaction.
#1. This is a limiting reagent (LR) problem. You know that because amounts are given for both reactants.
First you need to balance the equation.
2CuNO3 + MgCl2 ---> 2CuCl + Mg(NO3)2
mols CuNO3 = grams/molar mass = ?
mols MgCl2 = grams/molar mass = ?
Using the coefficients in the balanced equation, convert mols CuNO3 to mols CuCl.
Do the same and convert mols MgCl2 to mols CuCl.
It is likely that the value for mols CuCl will not be the same; the correct value in LR problem is ALWAYS the smaller value and the reagent responsible for that number is the LR. That gives you the answer for 2. The excess reagent is the other one and that's the answer for 1.For mass of the excess reagent, isn't that just 2 g (or did you mean something else)?
For 3, mass CuCl = mols CuCl x molar mass CuCl. This is the theoretical yield (TY)
For the other product, use the LR, convert to mols Mg(NO3)22 formed and convert to g Mg(NO3)2.
4. The actual yield (AY) is given in the problem as 3.50 g CuCl.
%yield = (AY/TY)*100 = ?
To answer these questions, you need to use the concept of stoichiometry, which is the quantitative study of reactants and products in a chemical reaction. Here's how you can approach each question:
A.) Suppose a chemical reaction starts with 5.00 g of copper (I) nitrate and 2.00 g of magnesium chloride.
1.) To determine the identity and mass of the excess reactant, you first need to calculate the number of moles for each reactant using their molar masses. The molar mass of Cu(NO3)2 is 187.56 g/mol, and the molar mass of MgCl2 is 95.211 g/mol. Divide the given masses by their respective molar masses to get the number of moles for each reactant.
2.) To determine the limiting reactant, compare the number of moles of each reactant to the stoichiometric ratio given by the balanced equation. The balanced equation shows that the ratio between Cu(NO3)2 and MgCl2 is 2:1. Multiply the number of moles of Cu(NO3)2 by 2 to account for this ratio. The limiting reactant is the one that produces fewer moles of the product.
3.) To determine the mass of each product that can be produced, you need to use the stoichiometric ratios provided by the balanced equation. Convert the number of moles of the limiting reactant to the respective product using the stoichiometric ratio given by the balanced equation. Then multiply the number of moles by the molar mass of the product to get the mass.
4.) To calculate the percent yield, divide the actual mass of copper (I) chloride collected (given as 3.50 g) by the theoretical mass of copper (I) chloride calculated in step 3. Then multiply by 100 to get the percent yield.
B.) Suppose a chemical reaction starts with 15.0 g of sodium nitrate and 13.1 g of potassium sulfate.
1.) Follow steps 1 and 2 as described above to determine the identity and mass of the excess reactant and the limiting reactant.
2.) Follow step 3 as described above to determine the mass of each product that can be produced.
3.) To calculate the percent yield, follow step 4 as described above by dividing the actual mass of potassium nitrate collected (given as 11.9 g) by the theoretical mass of potassium nitrate calculated in step 2. Multiply by 100 to get the percent yield.
Remember to always balance the equations before performing any calculations, as shown in the question.
Hope this helps! Let me know if you have any further questions.