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# Estimating specific heat and molecular weight from enthalpy

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Could you please take a look at this? I'm having trouble with #2 and #3. Thank you!

Observations:

#1 - Initial temperature of Iron shot (Fe) metal: 100°C
Final temperature of Iron shot (Fe) metal: 28°C
Initial temperature of water from calorimeter: 20°C
Final water temperature from calorimeter: 28°C

#2 - Estimate of specific heat for metal:
(use 1 cal/gm-°C for water)

#3 - Estimate the atomic weight of Iron shot (Fe) metal:

Instructions:

Step 1: Obtain metal sample in test tube. First add a test tube to the Lab. Add 100 gm of Iron Shot (Fe). Add a thermometer to the test tube so that you can record the initial temperature of the Fe.

Step 2: Prepare hot water bath and add test tube with metal. Obtain a 250 ml beaker. Add 150ml of water at room temperature to the beaker. Place test tube within beaker. Now heat the combined beaker test tube arrangement by heating with a bunsen burner until the Fe shot reaches the boiling point of water 100 °C.

Step 3: Place heated metal in calorimeter with water at room temp. Add Calorimeter to Lab. Add 100 ml of water at room temp 20 °C to calorimeter. Remove test tube from beaker. Pour the heated Iron into the calorimeter and close the calorimeter. Record the final temperature of the water.

https://brainmass.com/chemistry/energetics-and-thermodynamics/estimating-specific-heat-and-molecular-weight-from-enthalpy-414012

#### Solution Preview

So for #2 we want to find the specific heat, which as you recall was the "c" in q=mcdT.

We know the m of Fe is 100g. The initial T is 100 degrees, and the final T is 28 degrees.

The initial temp of the water was 20 degrees, and the final was 28. 150 mL of water is 150g ...

#### Solution Summary

How do we find the molecular weight of a substance and its specific heat if we know some data about its enthalpy? In this solution we explore, step-by-step, the math involved in solving these types of problems!

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