Answer:
a. Approximately 
.
b. Approximately 
.
Explanation:
The unit of concentration "
" is equivalent to "
", which means "moles per liter."
However, the volume of both solutions were given in mililiters 
. Convert these volumes to liters:
.
.
In a solution of volume 
where the concentration of a solute is 
, there would be 
(moles of) formula units of this solute.
Calculate the number of moles of 
formula units in each of the two solutions:
Solution in a.:
.
Solution in b.:
.
What volume of that 
(same as 
) solution would contain that many
For the solution in a.:
.
Convert the unit of that volume to milliliters:
.
Similarly, for the solution in b.:
.
Convert the unit of that volume to milliliters:
.
Answer:
Explanation:
Given parameters:
Mass of aluminium oxide = 3.87g
Mass of water = 5.67g
Unknown:
Limiting reactant = ?
Solution:
The limiting reactant is the reactant in short supply in a chemical reaction. We need to first write the chemical equation and convert the masses given to the number of moles.
Using the number of moles, we can ascertain the limiting reactants;
Al₂O₃ + 3H₂O → 2Al(OH)₃
Number of moles;
Number of moles = 
molar mass of Al₂O₃ = (2x27) + 3(16) = 102g/mole
number of moles = 
= 0.04mole
molar mass of H₂O = 2(1) + 16 = 18g/mole
number of moles = 
= 0.32mole
From the reaction equation;
1 mole of Al₂O₃ reacted with 3 moles of H₂O
0.04 mole of Al₂O₃ will react with 3 x 0.04 mole = 0.12 mole of H₂O
But we were given 0.32 mole of H₂O and this is in excess of amount required.
This shows that Al₂O₃ is the limiting reactant
Answer:
ionic bonds are the weakest bonds
Explanation:
5.6L of O2 means we have 0.25 moles of O2.
As, 1 mole has 6.023*10^23 molecules,
0.25 moles of O2 will have 0.25*6.023*10^23 molecules=1.50575*10^23 molecules
and as 1 molecule of O2 has 2 atoms, so, 1.50575*10^23 molecules will have 2*1.50575*10^23 atoms=3.0115*10^23 atoms of O.
