Answer:
5 g
Explanation:
From the question, we have,
Molarity of FeIII solution= 0.245 M
Volume of solution = 125 ml
From
number of moles= concentration × volume
We have;
Number of moles= 0.245 M × 125/1000
Number of moles = 0.031 moles
Molar mass of Fe III = 162.5g/moles
Mass of iron III = number of moles× molar mass = 0.031 × 162.5= 5 g
n
It would be approximately 489 g, rounded for significant figures. The calculator given answer would be 489.20326. To get that, all you have to do is take your 6.11 moles and multiply it by 80.066 (the molar mass) divided by 1 mol to cancel out the unit.
Answer:
The molar mass of the gas is 44 g/mol
Explanation:
It is possible to solve this problem using Graham's law that says: Rates of effusion are inversely dependent on the square of the mass of each gas. That is:

If rate of effusion of nitrogen is Xdistance / 48s and for the unknown gas is X distance / 60s and mass of nitrogen gas is 28g/mol (N₂):

6,61 = √M₂
44g/mol = M₂
<em>The molar mass of the gas is 44 g/mol</em>
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I hope it helps!
Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material PTFE (Teflon).
<u>We are given:</u>
Mass of ice = 21 grams
The ice is already at 0°c, the temperature at which it melts to form water
Molar heat of fusion of Ice = 6.02 kJ/mol
<u>Finding the energy required:</u>
<u>Number of moles of Ice: </u>
Molar mass of water = 18 g/mol
Number of moles = given mass/ molar mass
Number of moles = 21 / 18 = 7/6 moles
<u>Energy required to melt the given amount of ice:</u>
Energy = number of moles * molar heat of fusion
Energy = (7/6) * (6.02)
Energy = 7.02 kJ OR 7020 joules