# Find initial temp. of alcohol when copper and aluminum are added

• nlingraham
In summary, the initial temperature of the copper can be calculated using the equation Qa + Qc + Qe = 0, where Qa is the heat absorbed by aluminum, Qc is the heat absorbed by copper, and Qe is the heat absorbed by ethyl alcohol. By plugging in the given values and solving for Ti, the initial temperature of the copper is determined to be 268.51 K or -4.5 °C. However, a more accurate value may be obtained by checking for rounding errors, such as in the mass of ethyl alcohol used.
nlingraham
*Messed up title, should have been find initial temp of copper*

## Homework Statement

8.00 g of aluminum at 200 °C and 18.0 g of copper are dropped into 50.0 cm3 of ethyl alcohol at 15 °C. The temperature quickly comes to 26.0 °C. What was the initial temperature of the copper?

Density of ethyl alcohol = .789 g/ml

mass of ethyl alcohol = 39.45 g, .03495 kg

mass of copper = .018 kg

mass of aluminum = .008 kg

Tf = 299 K

Ti, alum = 473 K

Ti, eth = 288 K

c for aluminum = 900 J/kg*k

c for ethyl alcohol = 2400 J/kg*k

c for copper = 385 J/kg*k

## Homework Equations

Qa + Qc + Qe = macaΔT + meceΔT + mcccΔT = 0

## The Attempt at a Solution

Qa + Qc + Qe = macaΔT + meceΔT + mcccΔT = 0

=(.008)(900)(-174) + (.03945)(2400)(11) + (.018)(385)(299-Ti) = 0

Ti = 268.51 K or -4.5 °C

That's what I did, but it says not quite and tells to check for rounding errors. However, I didn't round anything until the very end, so I'm not quite sure where I went wrong. I also tried -4.494 but that was wrong too.

nlingraham said:
mass of ethyl alcohol = 39.45 g, .03495 kg

Could this be the error?

Well, I feel stupid now. thanks.

No need to worry. We all make slips like that. Hope it works out now.

I would first check my calculations to make sure they are accurate. Rounding errors can occur at any step in the calculation, so it's important to double check each step. Additionally, I would check to see if there are any units that need to be converted or if there are any missing units in the equation.

I would also consider the specific heat capacity values used for each substance. Are they accurate and appropriate for this specific scenario? Are there any other factors that could have affected the temperature change, such as heat loss to the surroundings?

Finally, I would also consider the significant figures used in the given values. Are they appropriate for the level of accuracy required in this calculation? It's possible that the answer could be slightly different depending on the number of significant figures used.

In summary, as a scientist, I would carefully review my calculations, check for appropriate units and significant figures, and consider any other factors that may have affected the temperature change.

## What is the purpose of finding the initial temperature of alcohol when copper and aluminum are added?

The purpose of this experiment is to determine the initial temperature of alcohol when two different types of metals, copper and aluminum, are added to it. This information can be used to understand the heat transfer between the metals and the alcohol, and can also provide insight into the specific heat capacities of these materials.

## What materials are needed for this experiment?

To find the initial temperature of alcohol when copper and aluminum are added, you will need: a thermometer, a beaker or container to hold the alcohol, copper and aluminum metal pieces, and a heat source (such as a hot plate or Bunsen burner).

## What is the process for conducting this experiment?

First, measure out a specific amount of alcohol (usually 100mL) and place it in the beaker. Next, use the thermometer to record the initial temperature of the alcohol. Then, add the copper and aluminum pieces to the alcohol and stir gently. As the metals heat up, the temperature of the alcohol will also increase. Continue stirring until the temperature stabilizes, and record the final temperature. Finally, use the initial and final temperatures to calculate the change in temperature.

## What factors can affect the accuracy of the results?

There are several factors that can affect the accuracy of the results in this experiment. These include the accuracy of the thermometer, the consistency of stirring, the amount of heat applied to the metals, and any external factors that may affect the temperature of the surroundings (such as drafts or changes in room temperature).

## What other applications can this experiment have?

This experiment can have various applications, such as understanding the heat transfer between different materials, determining the specific heat capacities of various substances, and exploring the concept of thermal equilibrium. It can also be used in industries that deal with heat transfer and materials, such as construction and engineering.

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