Does adding heat to an object always result in a temperature increase?

List one case when heat is added to something but its temperature remains constant?

In such a case, the heat energy is used to cause a phase change (solid to liquid or liquid to gas) rather than a temperature increase. This is known as latent heat because it cannot be detected by a temperature change. The amount of heat needed to change a mass m of a particular substance from one phase to another can be calculated from the formula

Q = mL

where L is the latent heat for that substance and the particular phase transition involved (freezing/melting or vaporization/condensation). The latent heat is the heat needed to change the phase of one unit mass of a given substance.

In the first part of this activity we will measure the latent heat of melting for ice. Open the simulation

at:https://media.pearsoncmg.com/bc/bc_0media_chem/chem_sim/calorimetry/Calor.php

Click on "Experiment" and then on "Run Experiment"

First, choose the 'solid' tab and scroll all the way down to below 'phase changes' and choose ice. Set the mass of the ice to 20 g and the temperature to 0 ⁰C.Record them below: We are designating these as 'ice' with the c subscript.

m_i=________ g

T_i=__________ ⁰C

Click the "Next" button. You must do this for the simulation to let you move on!

Now, choose a liquid to put in the calorimeter and choose water. Set the mass of the water to 100 g and the temperature to 40 ⁰C. Record them below: We are designating these as 'water' with the w subscript. Also check the box for "show specific heat" and record that as well. m_w= ________ g

T_w=__________ ⁰C

c_water = _______ J/g^oC

Click the "Next" button. You must do this for the simulation to let you move on!

Check the boxes "show graph view" and then press start. Sketch the temperature graph.

Record the temperature of the mixture when the simulation ends.

T_f = __________⁰C

Where did the heat that melted the ice come from? How do you know?

Calculate the heat lost by the warm water. Show your w Heat lost by water =__________ J.

According to the First Law of Thermodynamics (Conservation of Energy) the heat lost by one part of a system must be equal to the heat gained by another part of the system. That is heat lost = heat gained, or better yet

Heat lost by water = Heat gained by ice = heat gained by warming melted ice water + heat gained by melting ice.

From this equation, how much heat MUST be gained by the ice?

Heat gained by ice=__________ J.

As you can see, the heat gained by the ice goes into two places, melting the ice (latent heat) and then warming up the melted ice water to the final temperature. Now let's go after the heat gained by melting the ice water.

Mass of melted ice water = _________ g.

What do you think was the temperature of this melted ice just after it melted? Why? (do not use the graph to answer this question - recall the melting point of ice!)

Temperature of melted ice water =___________ ⁰C.

Calculate the heat absorbed by this melted ice water as it warms up to the final temperature. Show your work.

Heat gained by warming melted ice water = ____________ J.

Now you can use the conservation of energy equation to solve for how much energy went into melting the ice:

Heat gained by melting ice = ____________ J.

How much heat was needed to melt one gram of ice? Show your work.

Heat to melt one gram of ice = ___________ J/g

This is L_m, the latent heat of melting for ice. The accepted value is 334 J/g.

What do you think are the major sources of error in this experiment? How could the error be reduced?