To determine a limiting reagent ,first we have to write a balanced equation.
C8H5NO6 + NH2NH2 ------> C8H5N3O4 +2 H2O
C8H5N3O4 + Na2S2O4 -------->C8H7N3O2
stoiciometry of the reaction is 1:1
Now, we will calculate no. Of moles of reactant used:
1) C8H5NO6 used is 1 g;
No. Of moles = 1 g ×( 1 mole/ 211.13 g) = 0.0047 mole
2) NH2NH2 used is 2 mL
No. Of moles = volume of hydrazine × density of hydrazine× (1mole/ molecular weight of hydrazine)
= 2 mL×( 1.0045 g/mL) ×(1 mole/32.05 g) = 0.062 moles
3) Na2S2O4 used is 3 g
No. Of moles Na2S2O4 = 3 g x (1 mole / 174.11g) = 0.017 moles
The mole ratio of rxn 1 is 1:1 thus limiting reagent is C8H5NO6,, sine hydrazine is present in excess
Also in rxn 2 molar ratio between reactant is 1:1 , so C8H5N3O4 i a limiting reagent
Now we will calculate yield of reaction
Theoritical yield:
0.0047 mole of C8H5NO6 × ( 1 mole C8H5N3O4 / 1 mole C8H5NO6) = 0.0047 mole of C8H5N3O4
similarly, 0.0047 moles of C8H5N3O4 gives 0.0047 moles of luminol
0.0047 moles of luminol = 0.0047 mole luminol × (177.16 g luminol/ mole) = 0.8326 g luminol.....this is the theoritical yield.
To calculate percent yield = ( experimental yield / theoritical yield) ×100
Can someone pliz use the lab experiment n answer the question below. Especially calculating limiting reagent...