Answer:
44 grams/mole
Explanation:
<u>If 1 mol of XO₂ contains the same number of atoms as 60 g of XO3, what is the molar mass of XO₂?</u>
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60 grams of XO3 is one mole XO3, since it has the same number of atoms as 1 mole of XO2.
Let c be the molar mass of X. The molar mass of XO3 is comprised of:
X: c
3O: 3 x 16 = 48
Total molar mass of XO3 is = <u>48 + c</u>
We know that the molar mass of XO3 = 60 g/mole, so:
48 + c = 60 g/mole
c = 12 g/mole
The molar mass of XO2 would be:
1 X = 12
2 O = 32
Molar mass = 44 grams/mole, same as carbon dioxide. Carbon's molar mass is 12 grams.
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The question is incomplete,the complete question :
Calculate the molality of a 10.0% (by mass) aqueous solution of hydrochloric acid:
a) 0.274 m
b) 2.74 m
c) 3.05 m
d) 4.33 m
e) the density of the solution is needed to solve the problem
Answer:
The molality of a 10.0% (by mass) aqueous solution of hydrochloric acid is 3.05 mol/kg.
Explanation:
10.0% (by mass) aqueous solution of hydrochloric acid.
10 grams of HCl is present in 100 g of solution.
Mass of HCl = 10 g
Mass of solution = 100 g
Mass of solution = Mass of solute + Mass of water
Mass of water = 100 g - 10 g = 90 g
Moles of HCl = 
Mass of water in kilograms = 0.090 kg
Molality = 
The molality of a 10.0% (by mass) aqueous solution of hydrochloric acid is 3.05 mol/kg.
Molality is defined as the number of moles of solute in 1 kg of solvent.
molality of solution to be prepared is 0.50 molal
this means that in 1000 g of water there should be 0.50 mol of NaCl
if 1000 g of water should contain - 0.50 mol
then 750.0 g of water requires - 0.50 mol/kg x 0.750 kg = 0.375 mol
mass of NaCl in 0.375 mol - 58.5 g/mol x 0.375 mol = 21.9 g
therefore a mass of 21.9 g of NaCl is required
