<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles. We calculate as follows:
0.340 mol Br2 ( </span>6.022 x 10^23 molecules / mol ) = 2.05 x 10^23 molecules
It'll beginning to evaporate.
First a balanced reaction equation must be established:

→

Now if mass of aluminum = 145 g
the moles of aluminum = (MASS) ÷ (MOLAR MASS) = 145 g ÷ 30 g/mol
= 4.83 mols
Now the mole ratio of Al : O₂ based on the equation is 4 : 3
[
4Al +
3 O₂ → 2 Al₂O₃]
∴ if moles of Al = 4.83 moles
then moles of O₂ = (4.83 mol ÷ 4) × 3
=
3.63 mol (to 2 sig. fig.)
Thus it can be concluded that
3.63 moles of oxygen is needed to react completely with 145 g of aluminum.
Answer:
The answer to your question is 0.10 M
Explanation:
Data
Molarity = ?
mass of Sucrose = 125 g
volume = 3.5 l
Formula
Molarity = moles / volume
Process
1.- Calculate the molar mass of sucrose
C₁₂H₂₂O₁₁ = (12 x 12) + (1 x 22) + (16 x 11)
= 144 + 22 + 176
= 342 g
2.- Convert the mass of sucrose to moles
342 g of sucrose ------------------- 1 mol
125 g of sucrose -------------------- x
x = (125 x 1) / 342
x = 0.365 moles
3.- Calculate the molarity
Molarity = 0.365 / 3.5
4.- Result
Molarity = 0.10
Mass and energy can not be created or destroyed, they may be able to just be converted, and neither one seems without the opposite. For this reason in closed systems, both mass and energy are conserved individually. " I hope this helps "