The solubility of a compound in water is 6.8g/100ml at 25°C..
Calculate the amount of water required to crystallize 10g of the compound. If the pure compound is collected at 25°C what is the maximum possible yield percent.
To calculate the amount of water required to crystallize 10g of the compound, we need to use the given solubility of the compound in water. The solubility is stated as 6.8g/100ml at 25°C.
To find the amount of water required, we can set up a proportion. Let's assume x is the volume of water needed in ml.
Using the proportion:
(solubility of the compound / volume of water) = (10g / x ml)
We know the solubility is 6.8g/100ml. Substituting these values into the equation:
(6.8g/100ml) / x = 10g / x
Now, cross-multiply:
(6.8g * x) = (10g * 100ml)
Dividing both sides by 6.8:
x = (10g * 100ml) / 6.8g
Simplifying:
x ≈ 147.06 ml (rounded to two decimal places)
Therefore, approximately 147.06 ml of water is required to crystallize 10g of the compound.
To find the maximum possible yield percent, we need to determine the actual yield (mass of the compound collected) and divide it by the theoretical yield (mass of the compound that could be obtained if the reaction proceeded to completion), then multiply by 100%.
In this case, if the pure compound is collected at 25°C, the entire 10g should be obtained. Therefore, the actual yield is 10g.
To calculate the theoretical yield, we need to know the molar mass of the compound. Let's assume it is M grams/mol.
The moles of the compound in 10g can be calculated as:
moles = mass / molar mass
moles = 10g / M
Since the solubility is given as 6.8g/100ml, we can assume that 6.8g dissolves in 100ml (0.1L) of water. This gives us a 1:0.068 ratio (mass of compound:volume of water).
The volume of water used to crystallize the compound can be converted to liters:
volume of water = 147.06 ml / 1000 ml/L
volume of water = 0.14706 L
Since we have a 1:0.068 ratio of mass of compound to volume of water, we can multiply the volume of water by 0.068 to find the mass of the compound that can be dissolved:
mass of compound = 0.14706 L * 0.068g/mL
mass of compound = 0.00999528g
Therefore, the maximum theoretical yield is approximately 0.00999528g.
To find the maximum possible yield percent:
yield percent = (actual yield / theoretical yield) * 100%
yield percent = (10g / 0.00999528g) * 100%
yield percent ≈ 1000% (rounded to two decimal places)
Therefore, the maximum possible yield percent is approximately 1000%.