The volume of 5.00 M HF that will react with 4.72 g of calcium hydroxide is 0.0256 L
calculation
2HF + Ca(OH)₂ → CaF₂ + 2H₂O
Step 1: find the moles of Ca(OH)₂
moles= mass÷ molar mass
from periodic table the molar mass of Ca(OH)₂ = 40 +( 16+1)₂= 74 g/mol
moles = 4.72 g÷ 74 g/mol =0.0638 moles
Step 2: use the moles ratio to determine the moles of Hf
from the equation above HF: Ca(OH)₂ is 2:1
therefore the moles of HF = 0.0638 moles x 2/1 =0.1276 moles
Step 3: find the volume of HF
volume=moles /molarity
molarity =5.00 M = 5.00 mol/L
=0.1276 moles / 5.00 mol/l =0.0256 L
