The % yield of Hf is 91. 8%
calculation
% yield = actual mass/ theoretical mass x100
actual mass = 2.85 Kg
calculate the theoretical mass
by first write the equation for reaction
CaF2 +H2SO4 → 2HF + CaSO4
find the moles of CaF2 used
moles = mass/molar mass
mass = 6.05Kg = 6.05 x1000 =6050 Kg
molar mass of CaF2 = 40 + (19 x2) = 78 g/mol
moles= 6050/ 78 = 77.6 moles
by use of mole ratio between CaF2 to HF which is 1:2 the moles of HF is therefore = 77.6 x2 =155.2 moles of Hf
find the theoretical mass of HF = moles x molar mass ( 1 +19=20g/mol)
= 155.2 moles x 20 g/mol = 3104 grams = 3104 /1000 = 3.104 Kg
The % yield is therefore = 2.85 Kg/ 3.104 Kg x100 = 91.8%
Unit cells.
They are the smallest group of atoms that take form of a crystal and can repeat in 3 dimensions.
About 484 million miles
Fifth Planet from Our Star
Jupiter orbits about 484 million miles (778 million kilometers) or 5.2 Astronomical Units (AU) from our Sun (Earth is one AU from the Sun).
There you go. I gave you a image.
