100 g of an inorganic compound x.5h2o containing a volatile impurity was kept in an oven at 150 degree celcius for 60 minutes. the weight of residue after heating is 8g. the percentage of impurity in x was?

              150°C
X*5H₂O    →    X + 5H₂O↑

m₀=100 g
m(X)=8 g
M(H₂O)=18.0 g/mol
n(H₂O)=5 mol

the mass of the water 
m(H₂O)=M(H₂O)n(H₂O)
m(H₂O)=18.0*5=90 g

the mass of the residue after removal of water
m'(X)=100-90=10 g

the percentage of impurity in X*5H₂O
w(imp)=[m'(X)-m(X)]/m₀

w(imp)=[10-8]/100=0.02 (2%)

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The word freedom has many connotations, which is probably why Wilson uses it in his speech. He’s trying to appeal to a broad audience of Americans, and freedom is a democratic concept, which most Americans can relate to.

And these are the “requirements”:

•the denotation of the word freedom

•the connotation of the word freedom

•the emotional effect on the audience

•the change in meaning over the course of the text

•the fact that freedom means many things to many people