Answer:
65.08 g.
Explanation:
- For the reaction, the balanced equation is:
<em>2AlCl₃ + 3Br₂ → 2AlBr₃ + 3Cl₂,</em>
2.0 mole of AlCl₃ reacts with 3.0 mole of Br₂ to produce 2.0 mole of AlBr₃ and 3.0 mole of Cl₂.
- Firstly, we need to calculate the no. of moles of 36.2 grams of AlCl₃:
<em>n = mass/molar mass</em> = (36.2 g)/(133.34 g/mol) = <em>0.2715 mol.</em>
<u><em>Using cross multiplication:</em></u>
2.0 mole of AlCl₃ reacts with → 3.0 mole of Br₂, from the stichiometry.
0.2715 mol of AlCl₃ reacts with → ??? mole of Br₂.
∴ The no. of moles of Br₂ reacts completely with 0.2715 mol (36.2 g) of AlCl₃ = (0.2715 mol)(3.0 mole)/(2.0 mole) = 0.4072 mol.
<em>∴ The mass of Br₂ reacts completely with 0.2715 mol (36.2 g) of AlCl₃ = no. of moles of Br₂ x molar mass</em> = (0.4072 mol)(159.808 g/mol
) = <em>65.08 g.</em>
Answer:
Potassium permanganate has a molar mass of 158.04 g/mol. This figure is obtained by adding the individual molar masses of <em><u>four oxygen atoms</u></em>, <em><u>one manganese atom</u></em> and <em><u>one potassium atom</u></em>
Explanation:
Democritus, a Greek philosopher, first developed the idea of atoms (around 460 B.C., I believe).
Hope this helps!
Answer:
0.156mol
Explanation:
Number of moles of a substance can be calculated from its mass by dividing its mass by molar mass i.e.
Number of moles (n) = mass/molar mass
Molar mass of PbCl4 is as follows, where Pb = 207.2g/mol, Cl = 35.5g/lol
PbCl4 = 207.2 + 35.5(4)
= 207.2 + 142
= 349.2g/mol
Using: mole = mass/molar mass
mole = 54.32 grams ÷ 349.2g/mol
mole = 0.1555
mole = 0.156mol
Answer:
Approximately 6.81 × 10⁵ Pa.
Assumption: carbon dioxide behaves like an ideal gas.
Explanation:
Look up the relative atomic mass of carbon and oxygen on a modern periodic table:
Calculate the molar mass of carbon dioxide
:
.
Find the number of moles of molecules in that
sample of
:
.
If carbon dioxide behaves like an ideal gas, it should satisfy the ideal gas equation when it is inside a container:
,
where
is the pressure inside the container.
is the volume of the container.
is the number of moles of particles (molecules, or atoms in case of noble gases) in the gas.
is the ideal gas constant.
is the absolute temperature of the gas.
Rearrange the equation to find an expression for
, the pressure inside the container.
.
Look up the ideal gas constant in the appropriate units.
.
Evaluate the expression for
:
.
Apply dimensional analysis to verify the unit of pressure.