Why are chemicals faster when heated?

Question

I'm concluding a science investigation which involved reacting marble with hydrocloric acid (CaCO3), and timing the speed it takes. However, one of the questions is 'Answer why reactions are faster when heated - using scientific knowledge and terms'. Anybody help?

Answer 1

Any chemical reaction is based on a flow of energy. Provide more energy and you can then make the reaction faster, as the energy is more abundant to allow the compounds to react, and each molecule will then get to the proper energy level required to react at a faster rate.

Answer 2

I gather your doing your GCSE's so this is what I put:

When hydrochloric acid is heated, kinetic energy is given to the molecules from the heat. This then causes the particles of hydrogen and chlorine to move about quicker, thus ensuing more collisions, bopth in speed and rate. The more collisions at a higher speed, the higher the rate as the particles break the bonds and join together to make new ones.

Hope this helps!!!!

Answer 3

When you heat, the molecules have more vibrational kinetic energy. There is hence a greater proportion of molecules which now have an energy greater than the activation energy. The activation energy is that minimum amount of energy required to start a reaction.

The greater their kinetic energy, the more collisions between molecules of the two reactants will happen during an equal period of time and more effective collisions (those which result in a product being formed) will occur. Hence the reaction is faster.

Answer 4

I expect you already know this but heating gives the particles more kinetic energy so they move faster and have more collisions with other molecules thereby speeding up the reaction. Pupils often forget that the collisions are also harder so this improves the success rate and speeds up reaction. Hope this helps.

Answer 5

Quite simply,more energy. Why do you use hot water to clean plates? Same thing. If and object was totally devoid of energy it would become crystalline, and oddly more complex than a thing which was full of energy. The state, mass, and type of thing in question really don't matter. What we call 'heat' is energy, what we call 'cold' is lack of energy. You can't do anything without energy, so more of it makes things happen faster.

Here's an equation for you

Heat is energy which makes things happen faster.

If your grading board don't understand that because the words are too long for them and contain grammar, you can always wax philosophical and say

"You don't need an equation to wash dishes, you just wash them." Which in the context of an urban myth, always seems to work, but in real life usually = stares and an out-of-hand failing mark.



A Taoist.



...Oh dear, my coffee appears to of stopped radiating...^.^

Answer 6

Reactions are faster when heated because the reacting particles have more energy at a higher temperature. When they have more energy they move faster. In moving faster there is more chance of a collision between reacting particles. Because there is more chance of a collision between particles, then there is a greater chance of a successful collision.

Answer 7

When you heat matter, you increase the Kinetic Energy of the particles (they move around faster). For atoms to react together, they have to successfully come into contact with each other. Slow atoms have fewer sucessful contacts than fast ones. Ergo, heating a reaction causes it to go faster.

Answer 8

Reaction rate is indeed a function of temperature:
k(T) = A*exp(-Ea/R*T)

So the larger T is the smaller the negative exponent will be making the overall rate expression greater.

By the way this is called the Arrhenius Equation.

Answer 9

I remember this experiment from my 2nd year at senior school! It was fun, except the guy next to me dipped his hands in Hydrochloric Acid for a dare. :)

Molecules VIBRATE when heated up, and so they gradually move faster and faster, bumping into on another. Don't write this down though, I'm probably wrong, it's been ages since I did chemistry!

Answer 10

The rate of a reaction doubles with a 10'C increase.

No idea how!