This is a lab I have, but have no clue what to do. Please do out the steps so i can understand.
Reactions and Data:
NaOH(s)--> Na1+(aq)+ OH1-(aq)
(Heat of solution of NaOH)
This reaction involves adding solid NaOH to water and watching the temperature change as it dissolves.
Trial 1: 1.98 g of solid NaOH is dissolved in 106.5 mL of water. The temperature goes from 22.00°C to 26.50°C.
Hints:Remember that you are heating water. Use the formula Q = C x M x DT. The volume of water used equals the volume of whatever solution you are using, be it NaOH or HCl. The volume must be converted to mass (1 mL of water has a mass of 1 g). The mass must be reported in kilograms.
Questions and Calculations
For each of the three reactions:
1) Calculate the heat evolved in each trial (Q).
2) Calculate the moles of NaOH used in each trial (mol).
3) Calculate how much heat would be evolved if 1 mole of NaOH was used for each trial (Q/mol).
4) Calculate the average heat per mole in each of the 3 reactions.
How can I help? The instructions are plain:
1. Calculate q from mass H2O x heat capacity H2O x delta T H2O.
2. moles NaOH = grams NaOH/molar mass NaOH.
3. q you found/moles NaOH will give you q/mol
4. Average the results of the trials.
To answer the questions and perform the calculations, you will need to follow these steps:
1) Calculate the heat evolved in each trial (Q):
- Use the formula Q = C x M x ΔT, where Q is the heat evolved, C is the specific heat capacity of water (4.18 J/g°C), M is the mass of water, and ΔT is the change in temperature.
- First, convert the volume of water used to mass by multiplying it by the density of water, which is 1 g/mL. In this case, 106.5 mL of water is used, so the mass of water is 106.5 g.
- Next, calculate the change in temperature by subtracting the initial temperature from the final temperature: ΔT = 26.50°C - 22.00°C = 4.50°C.
- Finally, substitute the values into the formula and calculate the heat evolved for each trial.
2) Calculate the moles of NaOH used in each trial (mol):
- Use the molar mass of NaOH (22.99 g/mol for Na + 16.00 g/mol for O + 1.01 g/mol for H) to calculate the number of moles of NaOH used.
- Divide the mass of NaOH used in each trial by its molar mass to get the number of moles.
3) Calculate how much heat would be evolved if 1 mole of NaOH was used for each trial (Q/mol):
- Divide the heat evolved in each trial by the number of moles of NaOH used in that trial.
4) Calculate the average heat per mole in each of the 3 reactions:
- Take the sum of the values calculated in step 3 for the three trials and divide it by 3.
By following these steps, you should be able to answer the questions and perform the necessary calculations for the lab.