A 0.8870g sample of a mixture of nacl and nan03 is dissolved in water, and the solution is then treated with an excess of AGN03 to yield 1.913g of agcl. Calculate the percent by mass of the nacl in the mixture.
1.913g / 143 = 0.0133
x/58 ( 0.8870g -x) y/85 = 0.0133
0.01529 - 0.01724x + 0.01176x = 0.0133
x= 0.00199/0.00548
= 0.363/0.8870g x 100
=41%
100g - 41g = 59g
The right answer 87.87%
Who helps me step by step
The problem does not require simultaneous equations.
I would use 143.32 for molar mass AgCl and mols AgCl = 1.913/143.32 = 0.1334
mols NaCl = mols AgCl
g NaCl = mols NaCl x molar mass NaCl = 0.01334 x 58.44 = 0.7800 g
% = (0.7800g/0.8870g)*100 =87.94%
To calculate the percent by mass of NaCl in the mixture, you need to follow the steps outlined in the problem. Here's how you can do it step by step:
Step 1: Determine the mass of AgCl formed
Given that 1.913g of AgCl is formed, use the molar mass of AgCl (143g/mol) to calculate the number of moles:
moles of AgCl = mass of AgCl / molar mass of AgCl
moles of AgCl = 1.913g / 143g/mol
moles of AgCl = 0.01336 mol
Step 2: Determine the number of moles of NaCl and NaNO3
Let's assume the mass of NaCl in the mixture is x grams. Then, the mass of NaNO3 in the mixture would be (0.887g - x) grams.
Calculate the number of moles for each compound using their respective molar masses (NaCl: 58g/mol, NaNO3: 85g/mol):
moles of NaCl = mass of NaCl / molar mass of NaCl
moles of NaCl = x g / 58g/mol
moles of NaNO3 = mass of NaNO3 / molar mass of NaNO3
moles of NaNO3 = (0.887g - x) g / 85g/mol
Step 3: Use stoichiometry to equate moles of AgCl and NaCl
Since AgNO3 reacts with NaCl to form AgCl, you can set up a balanced equation:
AgNO3 + NaCl -> AgCl + NaNO3
The stoichiometric ratio between AgCl and NaCl is 1:1.
So, the moles of AgCl formed should be equal to the moles of NaCl:
0.01336 mol = moles of NaCl = moles of NaNO3
Step 4: Solve for x to find the mass of NaCl
Since the moles of NaCl and NaNO3 are equal, you can create an equation and solve for x:
moles of NaCl = x g / 58g/mol = 0.01336 mol
x g = 0.01336 mol * 58g/mol
x g = 0.7739 g
Step 5: Calculate the percent by mass of NaCl in the mixture
The percent by mass is given by:
percent by mass = (mass of NaCl / total mass of the mixture) * 100
percent by mass = (0.7739 g / 0.8870 g) * 100
percent by mass = 87.13 %
Therefore, the percent by mass of NaCl in the mixture is approximately 87.13%.
Note: The answer you provided (87.87%) may be due to rounding errors in the calculations.