Answer:
Mole fraction O₂= 0.43
Explanation:
Mole fraction is the moles of gas/ total moles.
Let's determine the moles of each:
Moles O₂ → 15.1 g / 16 g/mol = 0.94
Moles N₂ → 8.19 g / 14 g/mol = 0.013
Moles H₂ → 2.46 / 2 g/mol = 1.23
Total moles = 2.183
Mole fraction O₂= 0.94 / 2.183 → 0.43
Answer: 
Explanation:
Depression in freezing point is given by:
= Depression in freezing point
i= vant hoff factor = 1 (for non electrolyte like urea)
= freezing point constant = 
m= molality
Weight of solvent (X)= 950 g = 0.95 kg
Molar mass of non electrolyte (urea) = 60.06 g/mol
Mass of non electrolyte (urea) added = ?
Thus urea was dissolved.
Balanced equation: 2Fe + 3H2O → Fe2O3 +3H2
Convert g to mols:
285/55.845 = 5.1034 mols
Mole ratio of Iron and Iron (III) Oxide: 2:1
5.1034/2 = 2.5517 mols
Empirical formula is calculated as follows
calculate the moles of each element, that is % composition/ molar mass
molar masses ( Si= 28.09g/mol , Cl= 35.5 g/mol, I=126.9 g/mol)
moles of silicon = 7.962/28.09g/mol= 0.283 moles
moles of chlorine = 20.10 / 35.5g/mol = 0.566 moles
moles of iodine= 71.94 / 126.9 g/mol= 0.567 moles
divide each mole with smallest mole (0.283)
that is silicon = 0.283/0.283= 1 mole
chlorine = 0.566/0.283= 2 mole
Iodine= o.567/0.283= 2 moles
empirical formula is therefore= SiCl2I2
Answer:
1. 43.44g of HCl
2. 26.67 L of HCl
Explanation:
1) Molarity of a solution = number of moles (n) ÷ Volume (V)
According to the provided information in this question,
V = 350 mL = 350/1000 = 0.350L
Molarity = 3.4 M
Using Molarity = n/V
3.4 = n/0.350
n = 3.4 × 0.350
n = 1.19mol
Using the formula below to calculate the mass of HCl;
mole = mass/molar mass
Molar mass of HCl = 1 + 35.5 = 36.5g/mol
mole = mass/MM
mass = 1.19 mol × 36.5g/mol
mass = 43.44g of HCl
2) At STP, HCl has a pressure of 1atm, a temperature of 273K
V = ?
n = 1.19 mol
R = 0.0821 Latm/molK
Using PV = nRT
V = nRT/P
V = 1.19 × 0.0821 × 273/1
Volume = 26.67L
