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
mixas84 [53]
2 years ago
11

Describe an example of an endothermic and exothermic reaction. For each of your reactions, identify whether it is a physical or

chemical change and explain how the reaction supports the law of conservation of mass.
Biology
2 answers:
Valentin [98]2 years ago
8 0

Answer:

he sum of the enthalpies of the reactants is greater than the products, the reaction will be exothermic.

Explanation:

Verdich [7]2 years ago
4 0

Answer:

Explanation:Endothermic reactions

Photosynthesis

Photosynthesis is the chemical reaction that takes place in green plants, which uses energy from the sun to change carbon dioxide and water into food that the plant needs to survive, and which other organisms (such as humans and other animals) can eat so that they too can survive. The equation for this reaction is:

6

CO

2

(g)

+

6

H

2

O (l)

+

energy

→

C

6

H

12

O

6

(s)

+

6

O

2

(g)

Photosynthesis is an endothermic reaction. Energy in the form of sunlight is absorbed during the reaction.

The thermal decomposition of limestone

In industry, the breakdown of limestone into quicklime and carbon dioxide is very important. Quicklime can be used to make steel from iron and also to neutralise soils that are too acid. However, the limestone must be heated in a kiln (oven) at a temperature of over

900

℃

before the decomposition reaction will take place. The equation for the reaction is shown below:

CaCO

3

(s)

→

CaO (s)

+

CO

2

(g)

Exothermic reactions

Combustion reactions

The burning of fuel is an example of a combustion reaction, and we as humans rely heavily on this process for our energy requirements. The following equations describe the combustion of a hydrocarbon such as petrol

(

C

8

H

18

)

:

fuel + oxygen

→

heat + water + carbon dioxide

2

C

8

H

18

(l)

+

25

O

2

(g)

→

16

CO

2

(g)

+

18

H

2

O (g)

+

heat

This is why we burn fuels (such as paraffin, coal, propane and butane) for energy, because the chemical changes that take place during the reaction release huge amounts of energy, which we then use for things like power and electricity. You should also note that carbon dioxide is produced during this reaction. The chemical reaction that takes place when fuels burn has both positive and negative consequences. Although we benefit from heat, power and electricity the carbon dioxide that is produced has a negative impact on the environment.

Respiration

Respiration is the chemical reaction that happens in our bodies to produce energy for our cells. The equation below describes what happens during this reaction:

C

6

H

12

O

6

(s)

+

6

O

2

(g)

→

6

CO

2

(g)

+

6

H

2

O

(l)

+

energy

In the reaction above, glucose (a type of carbohydrate in the food we eat) reacts with oxygen from the air that we breathe in, to form carbon dioxide (which we breathe out), water and energy. The energy that is produced allows the cell to carry out its functions efficiently. Can you see now why you must eat food to get energy? It is not the food itself that provides you with energy, but the exothermic reaction that takes place when compounds within the food react with the oxygen you have breathed in!

Fact:

Lightsticks or glowsticks are used by divers, campers, and for decoration and fun. A lightstick is a plastic tube with a glass vial inside it. To activate a lightstick, you bend the plastic stick, which breaks the glass vial. This allows the chemicals that are inside the glass to mix with the chemicals in the plastic tube. These two chemicals react and release energy. Another part of a lightstick is a fluorescent dye which changes this energy into light, causing the lightstick to glow! This is known as phosphorescence or chemiluminescence.

You might be interested in
The table below summarizes Mendel’s results for the F2 generation. Mendel’s Results Plant height 787 tall 277 short Flower color
Gnom [1K]

Answer:

2001

Explanation:

This question showcases a table that displays Mendel's results (figures) when he crossed pea plants and observed different characters in the plant. Mendel worked with different phenotypic characteristics in the pea plant.

According to the table, the result were for seven characteristics including height, flower color, flower position, pod color, pod shape, seed color, seed shape. Based on the observation of the number of F2 offsprings that possessed dominant trait and recessive trait for each character, we will notice that it follows an approximate phenotypic ratio of 3:1

1. Plant height 787 tall 277 short (3:1)

2. Flower color 705 purple 224 white (3:1)

3. Flower position 651 middle of stem 207 end of stem (3:1)

4. Pod color 428 green 152 yellow (3:1)

5. Pod shape 882 inflated 299 constricted (3:1)

6. Seed color 6,022 yellow X green

7. Seed shape 5,474 smooth 1,850 wrinkled (3:1)

This 3 dominant : 1 recessive ratio is the ratio got in the F2 offsprings when he observed the seven characteristics in pea plants. Hence, the seed color will also follow the same 3:1 ratio

Therefore, 2001 is the result Mendel obtained in the F2 offsprings for the recessive trait of seed color characteristics in his experiment, which actually depicts the 3:1 ratio. Hence, X (green seed color) is 2001

8 0
3 years ago
Read 2 more answers
What are the benefits of using windmills or wind turbines as compared to burning fossil fuels?
atroni [7]
It'll be much cleaner for the environment. 
3 0
3 years ago
A grandfather has an x-linked disease. His wife does not have the disease and she is not a carrier for it. What is the probabili
kotykmax [81]

There is 50% probability that their daughter's son will have the disease, because daughter chromosomes are XX , and the X from father will have x- linked disease, now in next generation the son will have XY chromosomes, Y is from father and X will from mother, now mother have two "XX", out of these two one carry x- linked disease, that means 50 percent chances of having disease in son.

3 0
3 years ago
Membrane proteins of hamster cells were marked with a blue dye and membrane proteins of human cells were marked with a green dye
Luden [163]
Fat membrane metabolic disorder facts hamster cells were marked with a blue dye and membrane proteins
8 0
3 years ago
The primary auditory cortex is located within the _____ cortical lobe.
Alla [95]
Parietal and frontal.. whichever one your looking for 
7 0
3 years ago
Other questions:
  • What happens to the human body when the hart rate increases
    6·2 answers
  • The nurse is caring for a patient who has been scheduled for a bronchoscopy. how should the nurse prepare the patient for this p
    10·1 answer
  • Which consequence of global warming is described as having an increase in growing season, changes in migration, and loss of spec
    9·2 answers
  • Traits will sort themselves into gamete independently of what other traits are doing.” This is Mendel’s law of __________.
    5·2 answers
  • Which formations are features of karst topography? Check all that apply.
    6·2 answers
  • The endocrine system regulates the body through hormone release. Like the nervous system, what does the endocrine system help ma
    6·1 answer
  • (GIVING BRAINLIEST AND THE REST OF MY POINTS!!!!!!!)
    10·1 answer
  • 100 POINTS which bone does not move when the muscle contracts
    5·2 answers
  • Enter an algebraic equation for the word sentence. Use x as your variable.
    9·1 answer
  • Which factor is a major cause of the changes that
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!