Answer:
2.5 moles of Al
Explanation:
We'll begin by calculating the number of mole in 127 g of Al₂O₃. This can be obtained as follow:
Mass of Al₂O₃ = 127 g
Molar mass of Al₂O₃ = 101.961 g/mol
Mole of Al₂O₃ =?
Mole = mass / molar mass
Mole of Al₂O₃ = 127 / 101.961
Mole of Al₂O₃ = 1.25 mole
Finally, we shall determine the number of mole of Al that reacted. This can be obtained as follow:
4Al + 3O₂ —> 2Al₂O₃
From the balanced equation above,
4 moles of Al reacted to produce 2 moles of Al₂O₃.
Therefore, Xmol of Al will react to produce 1.25 moles of Al₂O₃ i.e
Xmol of Al = (1.25 × 4)/2
Xmol of Al = 2.5 moles.
Thus, 2.5 moles of Al is needed for the reaction.
Answer:
p=m/v
m=mass:402g
v=volume:385ml
p=density:?
divide 402 by 385 to get 1.04 the density is 1.04ml
Density (p)= mass (g)/volume (ml)
Answer:
11.2 M
Explanation:
Given data:
Number of moles = 6.7 mol
Volume of solution = 0.6 L
Concentration /Molarity = ?
Solution:
Molarity:
It is number of moles of solute in to per kg or litters of solution. It can be calculated by the following formula.
Molarity = number of moles / Volume in L
Now we will put the values in formula.
Molarity = 6.7 mol / 0.6 L
Molarity = 11.2 mol/L
Molarity = 11.2 M
Answer:
Explanation:
%Carbon = mass of carbon / mas of C13H18O2) X100%
= 13X12/ (13X12+18+2X16)X100%
= 156/206) X100%= 75.7%
