Volume Ca(OH)2 = mL ?
Molarity = 0.35 M
Volume HI = 278.3 mL / 1000 => 0.2783 L
Molarity HI = 0.32 M
number of moles HI :
n = M x V
n = 0.32 x 0.2783
n = 0.089056 moles of HI
mole ratio :
Ca(OH)2 + 2 HI = CaI2 + 2 H2O
1 mole Ca(OH)2 ------------- 2 moles HI
moles Ca(OH)2 -------------- 0.089056 moles of HI
moles Ca(OH)2 = 0.089056 x 1 / 2
moles Ca(OH)2 = 0.089056 / 2
= 0.044528 moles of Ca(OH)2
Volume of Ca(OH)2 :
M = n / V
0.35 = 0.044528 / V
V = 0.044528 / 0.35
V = 0.127 L in mL :
0.127 x 1000 = 127 mL
hope this helps!
