In: Chemistry
a)How many mol are in 64.61 g of nickel(II) phosphite?
b)How many mol of carbon are in 30.6 g of aluminum carbonate?
c)What is the mass (in grams) of 1.01 mol of iron(III) chloride?
d)What is the mass of oxygen in 5.71 g of aluminum oxide?
Solution
a)
mass of nickel(II) phosphite = 64.61 g
molar mass of nickel(II) phosphite = 148.361 g/mol
Number of mole = mass / molar mass = (64.61 g)/(148.361 g/mol) = 0.435 mole (ANS)
b)
Mass of aluminum carbonate, Al2(CO3)3 = 30.6 g
molar mass of aluminum carbonate =233.987 g/mol
No. of mole of aluminum carbonate = (30.6 g)/(233.987 g/mol) = 0.131 mole
In 1 mole of Al2(CO3)3 = 3 mole of carbon present
hence, no.of mole of carbon = 3 x 0.131 mole = 0.392 mole
c)
molar mass of Iron (III) chloride =162.2 g/mol
No. of mole of Iron (III) chloride, AlCl3 = 1.01 mole
mass of Iron(III) chloride, FeCl3 = (No. of mole of Iron(III) chloride) x (Molar mass of Ioron(III) chloride)
= (1.01 mole)x (162.2 g/mol) = 163.82 g (Ans)
d)
Mass of Aluminium oxide (Al2O3) = 5.71 g
Molar mass of Aluminium oxide (Al2O3) = 101.96 g/mol
No. of moles of Aluminium oxide (Al2O3) = (5.71 g)/(101.96 g/mol) = 0.0560 mole
In 1.0 mole of Al2O3, 3 mole of oxygen are present.
Therefore, No. of moles of oxygen in Al2O3 = 3 x 0.0560 mole = 0.1680 mole
Atomic mass of oxygen = 16 g/mol
the mass of oxygen = (No. of moles of oxygen )x (Molar mass of oxygen) = 0.1680 mole x 16 g/mol = 2.688 g (Ans)