Answer:
527.184 J of heat is removed from a 21 g water sample if it is cooled from 34.0 ° C to 28.0 ° C.
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
When the heat added or removed from a substance causes a change in temperature in it, this heat is called sensible heat.
In other words, the sensible heat of a body is the amount of heat received or transferred by a body when it undergoes a change in temperature without there being a change in physical state (solid, liquid or gaseous). The equation that allows to calculate this heat exchange is:
Q = c * m * ΔT
Where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT=Tfinal-Tinitial is the change in temperature.
In this case:
- c= 4.184
- m=21 g
- ΔT=Tfinal-Tinitial=28 °C - 34 °C=-6 °C
Replacing:
Q= 4.184 * 21 g* (-6 C)
Q= - 527.184 J
To lower the temperature, heat has to be given, for that the final temperature must be lower than the initial temperature; and it receives the name of transferred heat and has a negative value, as in this case.
<u><em>
527.184 J of heat is removed from a 21 g water sample if it is cooled from 34.0 ° C to 28.0 ° C.</em></u>
<h2>Project Reports</h2>
<h3>A) Mixture</h3>
This refers to the material that is made when different substances mix up physically and causes a reaction.
You can make on the project of Mixture -
- 1) Alloys
- 2)Colloids
- 3) Suspension
- 4) Solution
<h3>B) Compound</h3>
This refers to the chemical bond that holds different atoms tightly
You can make on the project of Compound -
- 1)Water
- 2)Methane
- 3)Carbon Dioxide
- 4) Sulfuric Acid
<h3>C) Elements</h3>
Based on the fact that the atom is the smallest indivisible part of an element, elements like phosphorous cannot be further broken down.
You can make on the project of Elements -
- 1) Mercury
- 2) Iron
- 3) Copper
- 4)Carbon
Read more about mixtures and compounds here:
brainly.com/question/491220
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Answer:
A
Explanation:
Let's illustrate this; see the attachment.
We see that Mrs. Jacobson is pushing to the right with a force of 100 N and there is another opposite force pushing with a force of 15 N. Since these are in opposite directions, we can say that the force opposite to Mrs. Jacobson is pushing the fridge -15 N to the right (instead of 15 N to the left).
The net force would then be:
100 N + (-15 N) = 85 N to the right
The answer is A.
Answer:
Explained below
Explanation:
When we heat a liquid, what happens is that the molecules of the liquid will absorb heat and thus develop kinetic energy that will make them move faster.
Now, as the liquid begins to boil, bubbles of will be formed inside the liquid and then rises to the surface. Now, when the temperature of the reaches 100°C which is the boiling point of a liquid, the molecules at the top of the liquid begin to change to gaseous state and escape in form of vapour.
Based on the periodic table, the element mendeleev called eka-manganese is now called technetium. Technetium<span> is a silvery-gray metal that tarnishes slowly in moist air. Hope this answers the question. Have a nice day. Feel free to ask more questions.</span>
