1. Calculate the MOLALITY (m=mol/kg) of the salt water solution. Note: Include the mass of ice AND volume of water when calculating the TOTAL MASS of the solvent (water). (1ml of water=1g of water.
Is my work correct? So what I did was,
Knowing m=mol/kg for molality, the following that has been measured include: mass of ice (50.51 g ICE), mass of NaCl(9.059 g NaCl), volume of water (100ml and to kg=0.1 or 0.100 kg for correct sig figs)
I took 50.51 g Ice divided by/ 18.0148 g Ice (molar mass of ICE) = 2.804 mol Ice
m=mol/kg... so, 2.804 mol Ice divided by/ 0.100 kg= 28.0 m of salt water solution.
Is this correct?
2. Calculate the expected boiling point of Your salt water solution based on your mass of NaCl(9.059 gNaCl)
Boiling point formula: Δ T bp = mKbp ...
I'm confused about what to put where. Please help. Greatly appreciated!
Also, for my graph
For part 1: Heating Curve of Water ..
Times:0-16.00 min ...Temperatures in order, (8°C, °8C, 5, 4, 18, 34, 58, 76, 91, 97, 97, 98, 99, 99, 100, 100°C)
For part 2: Heating curve of Salt water solution
Times: 0-16:00 min... Temperatures in order, (1°C, 0°C, 0°C, 0°C, 0°C, 5.1°C, 34.3, 53.1, 71.1, 86.2, 97.2, 99.1, 99.1, 99.8, 100.1, 100.1°C, and 99.9°C)
My question is: The graph box is 39 by 39. My scale for time (x-axis) is by 1's and ends at 19 (38th box) and my temperature (y-axis) I'm not sure what my scale should be. I want to try to use as much as the 39 by 39 if it's possible.
I'm sorry but I don't see the problem. I tried to decipher the problem from your work but I don't know where you started. It would help if you posted the original problem, then showed what you did.
1. To calculate the molality (m) of the salt water solution, you need to consider the total mass of the solvent (water). In this case, it includes the mass of both ice and water. You have the following measurements: mass of ice = 50.51 g, mass of NaCl = 9.059 g, and volume of water = 100 mL.
First, convert the volume of water to mass:
Volume of water in kg = 0.1 kg (since 1 mL of water is equal to 1 g)
Next, calculate the molality:
Molality (m) = moles of solute / mass of solvent
Since you want to calculate the molality of the salt water solution, you need to find the moles of NaCl.
Calculate the moles of ice:
Moles of ice = mass of ice / molar mass of ice
Molar mass of ice = 18.0148 g/mol
Moles of ice = 50.51 g / 18.0148 g/mol = 2.804 mol
Now, plug in the values to find the molality:
Molality (m) = moles of ice / mass of solvent
Molality (m) = 2.804 mol / 0.1 kg = 28.04 mol/kg
So, the correct molality of the salt water solution is 28.04 mol/kg.
2. To calculate the expected boiling point of your salt water solution, you need to use the boiling point formula: ΔTbp = mKbp.
In this formula, ΔTbp represents the change in boiling point, m is the molality, Kbp is the molal boiling point elevation constant (which is specific to the solvent), and you need to solve for ΔTbp.
To find the boiling point elevation constant (Kbp) for water, you can look it up in a reference source or use a commonly accepted value, which is approximately 0.512 °C/molal for water.
Now, plug in the values to find the expected boiling point:
ΔTbp = m * Kbp
m = 28.04 mol/kg (from the previous calculation)
Kbp = 0.512 °C/molal (boiling point elevation constant for water)
ΔTbp = 28.04 mol/kg * 0.512 °C/molal = 14.36 °C
Therefore, the expected boiling point elevation of your salt water solution is 14.36 °C.
Regarding the graph:
For the x-axis (time), you have a scale of 1 unit per minute. Since the maximum time is 16 minutes, you can set the x-axis scale from 0 to 16 with each unit representing 1 minute.
For the y-axis (temperature), you need to select a scale that allows you to utilize as much of the 39 by 39 box as possible. Based on the temperature range you provided, the minimum temperature is 0°C and the maximum is 100.1°C. You can divide this range into smaller intervals, such as increments of 10 degrees (0, 10, 20, ... up to 100). Another option would be to have every other unit represent 10 degrees (0, 20, 40, ... up to 100). Ultimately, choose a scale that gives you enough space to accurately plot the points, labels, and the trend of the graph.