Question

For the following reaction between Mohr's salt (iron asFeSo4(NH4)SO4 6H2O) and potassium dichromate(dichromate K2Cr2O7, determine the volume (in millimeters) of a 0.110 M solution of Mohr's salt that is needed to fully react with ).0600 L of a 0.110 potassium dichromate. (The reaction is shown in its ionic form in the presence of a strong acid.)

Cr2O2-7 + 6Fe2 + 14H+ arrow 2Cr3+ 6Fe3+ = 7H2O

For the same reaction what volume (in millimeters) of 0.110M potassium dichromate is required to fully react with 0.0600 L of a 0.110M solution of Mohr's salt?

Answer 1

Part A )

Cr2O2-7 (potassium dichromate)+ 6Fe2+ (Mohr's salt) + 14H+ --> 2Cr3+ + 6Fe3+ + 7H2O

molarity of mohr's salt M1= 0.11 M

moles of mohr's salt n1 = 6

volume of mohr salt mohr's salt V1= ?

molarity of potassium dichromate M= 0.11 M

moles of potassium dichromate n2 = 1

volume of potassium dichromate V2= 0.600 L

M1 V1 / n1 = M2 V2 /n2

0.11 x V / 6 = 0.11 x 0.6 / 1

V = 3.6 L = 3600 ml

Mohr's salt volume =3600 ml

part B)

same above formula

0.6 x 0.11 / 6 = 0.11 x V2 / 1

V2 = 0.1 L = 100 ml

potassium dichromate volume = 100 ml