1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Vedmedyk [2.9K]
3 years ago
9

How much heat is lost when 575 grams molten iron at 1825 k becomes solid iron at 293 k? The melting point or iron is 1811 k.​

Chemistry
1 answer:
Galina-37 [17]3 years ago
5 0

Answer:

146 kJ  

Explanation:

There are two heat flows in this question.  

Heat lost on cooling + heat lost on solidifying = 0  

                 q₁              +                 q₂                   = 0  

              mCΔT          +             nΔHsol              = 0  

Data:  

       m = 575 g  

       C = 0.449 J·K⁻¹g⁻¹  

    T_i = 1825 K  

    T_f = 1811 K  

ΔHsol = -13.8 kJ·mol⁻¹  

Calculations:  

(a) Heat lost on cooling  

ΔT = T_f - T_i = 1811 K - 1825 K = -14 K  

q₁ = mCΔT = 575 g × 0.449 J·K⁻¹g⁻¹ × (-14 K) = -361 J = -3.61 kJ  

(b) Heat lost on solidifying  

n = \text{575 g} \times \dfrac{\text{1 mol}}{\text{55.84 g}} = \text{10.30 mol}\\\\q_{2} = n\Delta_{\text{sol}}H = \text{10.30 mol} \times \dfrac{\text{-13.8 kJ}}{\text{1 mol}}= \text{-142.1 kJ}

(c) Total heat lost  

q = q₁ + q₂ = -3.61 kJ - 142.1 kJ = -146 kJ  

The heat lost was 146 kJ.

 

You might be interested in
9. Which statement provides evidence that supports the Big Bang Theory?* 2 points
liberstina [14]

The statement the chemical makeup of the universe has changed dramatically provides evidence that supports the Big Bang Theory (Option D).

<h3>What is the Big Bang Theory?</h3>

The Big Bang Theory is a widely accepted theory in physics that states all the universe began with a huge explosion and form then matters expanded in space at the same time that it is cooling.

Therefore, with this data, we can see that the Big Bang Theory states that the chemical composition of the universe associated with hydrogen and helium modified since this explosion.

Learn more about the Big Bang Theory here:

brainly.com/question/1973038

#SPJ1

4 0
1 year ago
Read 2 more answers
Which example is a trace fossil? {A} dinosaur egg {B} dinosaur footprint {C} dinosaur bone {D} shark tooth
viktelen [127]

dinosaur footprint

Explanation:

A dinosaur footprint is an example of a trace fossil. A trace fossil is a type of fossil that shows the activities of organisms that lived in the past.

  • Fossils are the preserved remains of organisms that lived several years ago.
  • Fossils are usually found in sedimentary rocks and thick layers of ice in temperate and polar regions.
  • Body fossils are the remains of the body parts of an organism that has been preserved. They can be skeletal parts, teeth, eggs e.t.c
  • A trace fossil shows the preserved remains of the activities of an organism.
  • They can be fingerprints, burrows and borings, feccal pellets e.t.c

Learn more":

fossils and evolution brainly.com/question/12790206

#learnwithBrainly

5 0
3 years ago
Read 2 more answers
Which of these types of changes is a physical change?
Cloud [144]

Answer:

answer is c

Explanation: cause there breaking it

8 0
3 years ago
Can I get some help?
Brut [27]
Yes, of course))))))
6 0
3 years ago
Which of the following is not true about water ? *
ale4655 [162]
Freezing point is -5 C
3 0
3 years ago
Other questions:
  • Are all acids dangerous? Give at least two examples to show what you mean.
    14·1 answer
  • Chromium-51 has a half life of 27.70 days. How much will be left after 166.2 days if
    10·1 answer
  • On the periodic table, the majority of elements are classified as
    10·2 answers
  • The Dendrite Of Nerve Cells Send Or Receive Information?
    12·1 answer
  • URGENT!!!!!!
    5·1 answer
  • How can you tell if an element is a metal or nonmetal?
    15·2 answers
  • Describe the path of an electron from a molecule of water to the sugar g3p
    9·1 answer
  • What does it mean to be an exact number? Give an example of an exact number.
    13·1 answer
  • I haven’t shifted before I tried like once a few months ago and I keep wanting to shift and last night I had a dream I did is th
    5·1 answer
  • Complete the chemical equations and balance them
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!