Determine the Δ H of a reaction Chemistry

background [prelab assignment (30 25points) due at the beginning of lab; put a copy in your lab NB]

1. calculate ΔH to dissolve solid NaOH in water (answer in kJ / mol) - theoretical value

2. based on ΔHfusion for water (6.0 kJ / 18 g water; - 44 kJ / 40 g NaOH), calculate the # grams of

a. ice

b. NaOH

to put into 100. mL of water to change the temperature by 10 °C [10 points].

3. sketch a data table for this lab containing entries for all required experimental measurements to determine ΔH to __ [10 points]

4. msds information on sodium hydroxide

purpose

determine experimentally ΔH to:

fulfill various aspects of the NGSS science & engineering standards.

materials

solid NaOH; ice; liquid water

coffee cup (calorimeter); thermometer; balance; gradulated cylinder, beaker

methods / analysis

student design

 

Content of lab report (45 35 points)

data analysis (15 points)

data table of your group's experimental data

based on preceding data table, experimentally determine ΔH to __ ; show calculation

dissolve NaOH  (in kJ / mole g NaOH)

melt ice (in kJ / mole g water)

disscussion [15 5 points]

calculate theoretical value of ΔH to dissolve NaOH  (in kJ / mole); look up ΔHfusion for water

error analysis - rationalize between experimental versus theoretical value for the preceding two ΔH values

reflection [15 poins]

describe / list three (std 1; std 2; std 3) NGSS science & engineering practices that correlates to an aspect of this laboratory activity; provide an example in the lab & this lab report that meets these practices

 

resource

example lab: ΔH to dissolve NaOH

writing mathematics