2agno3 (s) + mgcl2 (aq) --> 2agcl (s) + mg(no3)2 (aq) the student starts with 50.0 grams of mgcl2 and an excess of agno3. if she makes 125.1g of agcl, what is her percent yield?

 The percent yield  is 83.12%

  calculation

percent yield =  actual  yield / theoretical  yield x 100

actual yield =125.1 g

Theoretical yield  is calculated as below

Step 1:  find the  moles of MgCl₂

moles  = mass÷ molar mass

from periodic table the  molar mass of mgCl₂ =24.3 +(35.5 x2) =95.3 g/mol

moles = 50.0 g÷ 95.3 g/mol =0.525  moles

Step 2:  use the mole ratio to determine the moles of AgCl

from given equation MgCl₂: AgCl  is  1:2

therefore the moles of AgCl = 0.525  x2/1 =1.05 moles

Step 3: find the theoretical mass  AgCl

mass = moles x molar mass

from periodic table the molar mass of Agcl = 107.87 +35.5 =143.37 g/mol

mass = 1.05 moles x 143.37 g/mol =150.5 grams

The percent  yield  is therefore = (125.1 g/150.5)  x 100 = 83.12%

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.