Ammonium nitrate's endothermic dissolution drives an SC190 Unit 6 calorimetry lab report whose readings stay bracketed and whose sign of q is followed throughout. Searches like "sc 190 unit 6 assignment example", "sc190 unit 6 sample" and "sc190 unit 6 example" land here.
What a finished SC190 Unit 6 calorimetry lab report looks like
Five pages, sectioned the way every SC190 lab is. The data table lists, for each trial, [mass of NH4NO3], [mass of water], [initial temperature] and [final temperature], with the temperature change computed as final minus initial and carrying its negative sign. A temperature-time plot of [readings] shows the extrapolation back to the moment of mixing, correcting for heat leaking in from the room. The calculation appears once: q for the solution equals [mass of solution] times 4.184 J/g per degree Celsius times [temperature change], a negative number; q for the dissolution is its opposite, positive; dividing by moles of solute, [mass] over 80.04 g/mol, gives the enthalpy of solution in kilojoules per mole. The discussion compares that value with the literature figure of about +25.7 kJ/mol and names the direction each error source would push the result.
How a SC190 Unit 6 example is structured
Headings follow the standard lab sequence: purpose, background, procedure by reference, data, calculations, discussion and conclusion. The background sets out the sign convention in words, since it governs everything after: the system is the dissolving salt, the surroundings are the water, and heat gained by the system is heat lost by the water. Stated assumptions follow, a specific heat equal to pure water's, a solution density near 1.00 g/mL and a calorimeter that absorbs negligible heat unless a constant was measured. Calculations appear once in full with units, then results for each trial in a table with the mean and spread. The discussion is weighted most heavily and is organized by error source, each one named, assigned a direction and compared with the observed deviation. The conclusion states the enthalpy with sign, units and precision in a single sentence.
Temperature change keeps its sign
The change is written as final minus initial, a negative value here, and carried through the calculation so the endothermic result emerges from the arithmetic rather than a late correction.
System and surroundings named
The report defines the salt as the system and the water as surroundings before any number appears, which makes q for the dissolution the negative of q for the water.
Extrapolated temperature, not the lowest reading
The minimum on the temperature-time plot is corrected by extrapolating the warming line back to the mixing time, which accounts for heat leaking in from the room.
Kilojoules per mole, plus sign included
Heat is divided by moles dissolved, [mass] over 80.04 g/mol, and reported with a plus sign and kilojoules per mole, the three features graders look for first.
Heat leaks traced to their effect
Heat entering through the cup's walls would shrink the observed temperature drop and make the calculated enthalpy too small, and the discussion checks that direction against the result.
Where marks go in SC190 Unit 6
The costliest error on calorimetry reports is a sign lost somewhere between the water and the reaction, producing a negative enthalpy for a process that made the cup cold. Heat calculated from the mass of solute alone, rather than the whole solution, is the next frequent loss and understates q badly. Temperature change taken from the lowest reading without extrapolation costs method credit in sections that teach the correction. Results reported in joules when the prompt wants kilojoules per mole, or never divided by moles at all, lose unit marks. A discussion that settles for vague mistakes, or names heat exchange with the room without saying which way it would move the result, gives up the reasoning credit most rubrics carry. Assumptions left unstated, specific heat and density above all, account for the smaller deductions.
Get a SC190 Unit 6 example written to your instructions
Your temperatures, masses and trials stay your own; send along the Unit 6 lab handout, the SC190 rubric and the reaction or dissolution you measured. The model states the sign convention, chains each calculation, marks your readings as bracketed placeholders and sets out the error discussion by source. Delivery runs 24-48h; the first model is free.
SC190 Unit 6 questions, answered
Why is the enthalpy positive when the temperature went down?
Because the thermometer measures the water, not the dissolving salt. The water lost heat, so its q is negative. That heat went into the dissolution, so the process's q is positive, and at constant pressure the enthalpy change carries the same sign. An endothermic process always makes its surroundings colder, which is exactly what the cup showed.
Can the model report include my actual temperature readings?
No, and for a reason that protects you: those readings are the evidence that you ran the experiment. The model puts a labeled placeholder wherever a measured value belongs, [initial temperature], [final temperature], [mass of solute], and writes the heat calculation and error discussion around them, so entering your values completes the report.
How close to the literature value should my result be?
Coffee-cup setups often land within roughly ten to twenty percent of accepted values, sometimes further, because the cup exchanges heat with the room. The report is not graded on matching the literature; it is graded on an honest percent error and a discussion that explains the gap with named sources pushing in the right direction.