if 40g of KNO3 is dissolved in 100ml water at 25 C WHAT WILL FINAL TEMP BE? SHOW ALL WORK
You need to know the delta H solution.
IDK what that means??????
To determine the final temperature when 40g of KNO3 is dissolved in 100ml of water at 25°C, we can use the concept of heat transfer and the equation for heat transfer:
q = m * c * ΔT
where:
q is the heat absorbed or released
m is the mass of the solution
c is the specific heat capacity of the solution
ΔT is the change in temperature
To find the final temperature, we need to calculate the heat absorbed or released when dissolving KNO3, assuming no heat is lost to the surroundings.
1. Calculate the heat transferred, q:
q = m * c * ΔT
Here, m is the mass of the solution, which is the mass of KNO3 + mass of water.
mass of KNO3 = 40g, mass of water = 100g (since 1 ml of water has a mass of approximately 1g)
Therefore, m = 40g + 100g = 140g
2. Determine the specific heat capacity, c:
The specific heat capacity of water is approximately 4.184 J/g°C.
3. Calculate ΔT:
ΔT = T final - T initial
The initial temperature, T initial, is given as 25°C, and since the salt and water are at the same temperature, the final temperature, T final, is the same.
ΔT = T final - 25
4. Substitute the values into the equation and solve for T final:
q = m * c * ΔT
q = (140g) * (4.184 J/g°C) * (T final - 25)
Since no information about the direction of heat transfer is given, let's assume the heat is absorbed when KNO3 is dissolved, so q is positive.
q = (140g) * (4.184 J/g°C) * (T final - 25) > 0
Now we can solve for T final:
(140g) * (4.184 J/g°C) * (T final - 25) = 0
Simplifying the equation gives:
140 * 4.184 * (T final - 25) = 0
586.96 * (T final - 25) = 0
586.96 * (T final) - 586.96 * 25 = 0
586.96 * (T final) = 586.96 * 25
T final = 586.96 * 25 / 586.96
T final ≈ 25°C
Therefore, the final temperature is approximately 25°C.