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
suter [353]
3 years ago
9

Name three high temperature reactions

Chemistry
1 answer:
lions [1.4K]3 years ago
3 0

Explanation:

As you increase the temperature the rate of reaction increases. As a rough approximation, for many reactions happening at around room temperature, the rate of reaction doubles for every 10°C rise in temperature. You have to be careful not to take this too literally. It doesn't apply to all reactions. Even where it is approximately true, it may be that the rate doubles every 9°C or 11°C or whatever. The number of degrees needed to double the rate will also change gradually as the temperature increases.

Examples

Some reactions are virtually instantaneous - for example, a precipitation reaction involving the coming together of ions in solution to make an insoluble solid, or the reaction between hydrogen ions from an acid and hydroxide ions from an alkali in solution. So heating one of these won't make any noticeable difference to the rate of the reaction. Almost any other reaction you care to name will happen faster if you heat it - either in the lab, or in industry.

The explanation

Increasing the collision frequency

Particles can only react when they collide. If you heat a substance, the particles move faster and so collide more frequently. That will speed up the rate of reaction. That seems a fairly straightforward explanation until you look at the numbers! It turns out that the frequency of two-particle collisions in gases is proportional to the square root of the kelvin temperature. If you increase the temperature from 293 K to 303 K (20°C to 30°C), you will increase the collision frequency by a factor of:

(1)303293=1.017" role="presentation" style="display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 12px; text-indent: 0px; text-align: center; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; width: 10000em !important; position: relative;">303293=1.017(1)(1)303293=1.017

That's an increase of 1.7% for a 10° rise. The rate of reaction will probably have doubled for that increase in temperature - in other words, an increase of about 100%. The effect of increasing collision frequency on the rate of the reaction is very minor. The important effect is quite different . . .

The key importance of activation energy

Collisions only result in a reaction if the particles collide with enough energy to get the reaction started. This minimum energy required is called the activation energy for the reaction. You can mark the position of activation energy on a Maxwell-Boltzmann distribution to get a diagram like this:

Only those particles represented by the area to the right of the activation energy will react when they collide. The great majority don't have enough energy, and will simply bounce apart. To speed up the reaction, you need to increase the number of the very energetic particles - those with energies equal to or greater than the activation energy. Increasing the temperature has exactly that effect - it changes the shape of the graph. In the next diagram, the graph labeled T is at the original temperature. The graph labeled T+t is at a higher temperature.

If you now mark the position of the activation energy, you can see that although the curve hasn't moved very much overall, there has been such a large increase in the number of the very energetic particles that many more now collide with enough energy to react.

Remember that the area under a curve gives a count of the number of particles. On the last diagram, the area under the higher temperature curve to the right of the activation energy looks to have at least doubled - therefore at least doubling the rate of the reaction.

Summary

Increasing the temperature increases reaction rates because of the disproportionately large increase in the number of high energy collisions. It is only these collisions (possessing at least the activation energy for the reaction) which result in a reaction.

You might be interested in
Please explain:) I would really appreciate a step by step explanation if possible.
UNO [17]

The enthalpy change of the reaction, ΔH = -311 kJ

Enthalpy change involved in the reaction of 300 g of CO = -10972.5 kJ

<h3>What is the enthalpy change for the reduction of ethyne to form ethane?</h3>

The enthalpy change for the reaction is obtained from the summation of the enthalpies of the reactions of the intermediate steps according to Hess's law.

The equation of the reaction is given below:

  • C₂H₂ + 2 H₂ → C₂H₆

The enthalpy of the reaction, ΔH = ΔH₁ + 2ΔH₂ + (-ΔH₃)

ΔH = {(-1299) + (2 * -286) + (1560)}Kj

ΔH = -311 kJ

The equation for the methanation reaction is given below:

3 H₂O + CO → CH₄ + H₂O

The enthalpy for the methanation reaction is as follows:

ΔH = 1.5ΔH₁ + 0.5*(-ΔH₂) + ΔH₃ + -ΔH₄

ΔH = (-483.6 * 1.5) + (0.5 * 221.0) + (-802.7) + (393.5)

ΔH = -1024.1 kJ/mol

Molar mass of CO = 28 /mol

Enthalpy change involved in the reaction of 300 g of CO = 300/28 * -1024.1 kJ/mol

Enthalpy change involved in the reaction of 300 g of CO = -10972.5 kJ

In conclusion, the enthalpy changes are calculated from the enthalpy values of the  intermediate reactions.

Learn more about enthalpy changes at: brainly.com/question/26991394

#SPJ1

7 0
2 years ago
Consider these phylogenetic trees. The first tree is based on physical characteristics. The second tree is based on structure, g
kati45 [8]

Im not 100% sure, but I think the answer is C. If not, Im sorry for bothering you.

7 0
3 years ago
Read 2 more answers
Change 32L of carbon dioxide into moles of carbon dioxide
kaheart [24]
32L —> 32000g —> 727.116 Moles (rounded)
7 0
2 years ago
What property of these items do cm or mm measure: length, volume, mass or temperature?
UNO [17]

Answer:

length

Explanation:

cm measures length. Think of a ruler.

7 0
2 years ago
A statement that best describes a solution
PIT_PIT [208]
A solution is usualy a diluted liquid that cleans for example bleach solution.
6 0
2 years ago
Other questions:
  • The outer planets—Jupiter, Saturn, Uranus, and Neptune—are made up of which gases?
    6·2 answers
  • What types of intermolecular interactions are present in pure substances composed of the each of the three molecules below:
    14·1 answer
  • Which of the following is an sxample of using physical capital to save time and money
    15·1 answer
  • What 2 factors determine whether a collision between reactants is effective
    7·1 answer
  • Question 9
    12·1 answer
  • Please answer correctly !!!!!!!!!!! Will mark brainliest !!!!!!!!!!!!!!!!!!
    15·1 answer
  • What does a bird , beetle and a fungus have in common
    5·2 answers
  • Four students wrote different analogies to describe an electron before the formation of an ionic bond . Student A: A tug of war
    11·1 answer
  • The graph shows Mississippi’s electrical generation using various sources of energy for May 2013.
    9·2 answers
  • Raul designs a device to protect a raw egg from cracking when dropped from different heights. He wants his device to be as light
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!