Question

How many kilograms of HF are needed to completely react with 1.01 kg of UO₂?

Answer 1

The molar mass of UO2 267.04 gram/mol = 267.04 kg/kmol

The molar mass of HF 20.0 gram/mol = 20.0 kg/kmol

According to the reaction equation UO2 + 4HF—>UF4 + 2H2O

for 1 kmol of UO2 are needs 4 kmol of HF.

Given weight of $UO_2=1.01kg$

1kg=1000 g

$mol of UO_2= \frac{Given \; mass}{Molar\;man \;of \;UO_2} \\ = \frac{1010 \;g}{270.03\;gmol^-1}= 3.74 \; mol$

From balanced reschim

1 mol of $UO_2$ —> 4 mol of HF

3.74 mol of $UO_2$ —> 14.96 mol of HF

mol of HF needed= 14.96mol

man of HF needed=$mol\times molar \;mass=14.96mol \times 20.01g/mol=299.4g$

1g=0.001kg

Man of HF sepuired= 0.299 kg