If 60 g water is evaporated from the solution at the same time as the temperature is reduced from 25.0 to 0.0 degree celsius, what mass of KNO3(s) will recrystallize?
Do you have a chart or graph to follow?
yes. the solubility of KNO3(s) at 0.0 degree celsius is 15g KNO3/100g H2O. Also, A 320g sample of a saturated solution of KNO3(s) in water is prepared at 25.0 degree celsius (this is part of the info given). i don't know how to solve this.
some 1 help it is due 9 am tomorrow. for the chart the solubility curves at kno3 in any general chemistry text book.
the answer is 67 buddy
Did any of you guys get "How long should it take milk to sour at 45?
To determine the mass of KNO3(s) that will recrystallize, we need to follow a step-by-step process:
Step 1: Calculate the heat lost during cooling
The heat lost during cooling can be determined using the formula:
Q = m * C * ΔT
Where:
Q = heat lost (in Joules)
m = mass of the substance (in grams)
C = specific heat capacity (for water, it is around 4.18 J/g·°C)
ΔT = change in temperature (in °C)
In this case, the mass of water is given as 60 g, the specific heat capacity for water is 4.18 J/g·°C, and the change in temperature is 25.0 - 0.0 = 25.0 °C.
So, Q = 60 g * 4.18 J/g·°C * 25.0 °C
Step 2: Convert heat lost to energy required for evaporation
To convert the heat lost into the energy required for evaporation, we need to use the heat of vaporization for water, which is 40.7 kJ/mol.
1 kJ = 1000 J
1 mol of water = 18.015 g
So, the energy required for evaporation is:
Energy = (Q * 1000) / (18.015 g/mol)
Step 3: Convert energy required for evaporation to moles of water
To convert the energy required for evaporation into moles of water, we divide the energy by the molar heat of vaporization:
Energy (in J) / molar heat of vaporization (in J/mol) = moles of water
Step 4: Use the stoichiometry of the reaction to determine the moles of KNO3(s) formed
The balanced chemical equation for the reaction is:
2 KNO3(aq) → 2 KNO3(s)
From the equation, we can see that for every 2 moles of KNO3(aq) that evaporate, we get 2 moles of KNO3(s) in return. Therefore, the moles of KNO3(s) formed will be equal to the moles of water evaporated.
Step 5: Convert moles of KNO3(s) to mass of KNO3(s)
To convert moles of KNO3(s) to mass, we use the molar mass of KNO3, which is 101.11 g/mol.
Moles of KNO3(s) * Molar mass of KNO3 = Mass of KNO3(s)
Following these steps, you should be able to calculate the mass of KNO3(s) that will recrystallize.