Methods to Bring Physical and Chemical Changes Using Heat Light Pressure and Catalysts
Heraclitus, a Greek philosopher, quoted that “Change is the only constant in life”. The impacts that a change produces can help us identify it. Regardless of whether we are aware of it, people continue to see it daily. Whether it’s a day turning into a night or water freezing over. Although some changes take longer to manifest than others, some do so more quickly, however things change with time.
Additionally, a pencil loses length over time. When a substance is cooked, its qualities are altered. When heated, an iron bar becomes flaming hot, which can result in a color change which is visible to human eyes. A soccer ball is moved when we kick it. A child's weight and height fluctuate as they grow. For every change, there is some cause or reason, which is discussed below in this article.
What is Change?
Change happens when something undergoes a transformation in structure, location, dimension, colour, condition, look, and content as a result of an external or internal event. Either a persistent or interim modification will occur.
Now let's attempt to characterise the change in terms of science. It is an action that causes something to form or transform into something different from how it was before. For example, water is generated when the ice melts. As a result, it changes from a solid to a liquid state.
Types of Changes
There are different types of changes which occur around us, which are classified as below:
Slow and fast changes
Periodic and non-periodic changes
Reversible and irreversible changes
both man-made and natural changes
Positive and negative changes
Controlled and uncontrolled changes
Which is a Way to Make a Change Happen?
Humans look at a variety of change instances, including slow and fast change, reversible and irreversible change, wanted and unwanted change, physical and chemical change, etc. Different ways to make a change are listed below. By heating, cooling, exerting pressure, and combining, things can change with time. A closer look at other ways to bring change is explained below.
Changes generated by temperature: Temperature changes or fluctuations have the potential to bring forth change. Most of the time, such a change modifies the object's shape. For example, Water freezes and turns to ice when it is subjected to cold temperatures for an extended duration of time. In a similar way, water changes from a liquid to a gas when exposed to high heat. So, we may claim that it is caused by temperature.
Changes caused by pressure: By exerting a specific amount of pressure on an item, one can occasionally modify its shape. Whenever a sculptor turns statues out of stone, that will be among the best illustrations of this. He\she uses a chisel and a hammer to exert pressure on the rock, shaping it into a statue. Parallel to this, a goldsmith flattens a lump of gold by applying pressure on it before using it to fashion elaborate ornaments. As a result, one can assert that pressure can cause change.
Changes due to chemical mixing: When two compounds are combined, some changes take place. For example, when salt and water are combined, the salt dissolves and creates a salt solution, changing the composition of the salt. As a result, one can infer that chemical combinations may also cause change to happen.
How We Can Change?
In scientific terms, physically and mentally we change from our birth to our death. These changes can occur naturally or when any external force is applied to us.
Interesting Facts
We can return salt and water to their original state so that they can be combined once more to create an identical salt solution. So, adding salt to water is a reversible change.
This kind of alteration is also referred to as a physical change since salt and water don't interact. The majority of the physical alterations can be undone.
Mixing curd in warm milk is an irreversible change which is also referred to as chemical change since turning curd to milk again is not possible.
Key Features to Remember
Change happens when an entity faces certain factors which can be external or internal elements that result in a change in the entity's location, shape, colour, condition, look, or composition.
Changes can happen both in human beings and non-living things either naturally or by applying any external pressure.
Changes might be slow or fast, periodic or ad hoc, reversible or irreversible, and beneficial or unfavourable.
These modifications take place in a variety of ways via heating, cooling, exerting pressure, and combining two or more items.
FAQs on Other Ways To Bring A Change in Chemical Substances
1. What are the other ways to bring about a change in matter besides heating?
Other ways to bring about a change in matter besides heating include cooling, applying pressure, passing electricity, exposing to light, and mixing substances. These methods can cause either physical or chemical changes.
- Cooling: Freezing water to form ice, H2O(l) → H2O(s).
- Pressure: Compressing gases changes volume (Boyle’s law).
- Electricity: Electrolysis of water, 2H2O(l) → 2H2(g) + O2(g).
- Light: Photosynthesis uses light energy, 6CO2(g) + 6H2O(l) → C6H12O6(aq) + 6O2(g).
- Mixing substances: Acid–base neutralization reactions.
2. How does cooling bring about a physical change?
Cooling brings about a physical change by reducing the kinetic energy of particles, often causing a change of state without forming a new substance.
- Liquid water freezes: H2O(l) → H2O(s).
- Gas condenses: H2O(g) → H2O(l).
3. Can electricity cause a chemical change?
Yes, electricity can cause a chemical change through a process called electrolysis. In electrolysis, electrical energy breaks down compounds into simpler substances.
- Example: 2H2O(l) → 2H2(g) + O2(g)
4. How does light bring about a chemical reaction?
Light brings about a chemical reaction by supplying energy for a photochemical reaction. The energy from light helps break chemical bonds and form new ones.
- Example: Photosynthesis — 6CO2(g) + 6H2O(l) → C6H12O6(aq) + 6O2(g).
- Example: Decomposition of silver chloride — 2AgCl(s) → 2Ag(s) + Cl2(g) (in sunlight).
5. How does pressure bring about a change in matter?
Pressure brings about a change in matter by altering the volume and arrangement of particles, especially in gases. According to Boyle’s law, pressure and volume are inversely proportional at constant temperature.
- Compressing a gas decreases its volume.
- High pressure can liquefy gases, such as converting NH3(g) into liquid ammonia.
6. What happens when two substances are mixed to bring about a change?
When two substances are mixed, they may undergo a physical change (like dissolving) or a chemical reaction forming new substances.
- Physical example: NaCl(s) dissolving in water to form NaCl(aq).
- Chemical example: Neutralization — HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l).
7. Is dissolving a substance in water a chemical change?
Dissolving a substance in water is usually a physical change because no new substance is formed. For example:
- NaCl(s) → Na+(aq) + Cl-(aq).
8. How can a catalyst bring about a chemical change?
A catalyst brings about a chemical change by increasing the rate of a reaction without being consumed. It lowers the activation energy required for the reaction.
- Example: Decomposition of hydrogen peroxide — 2H2O2(aq) → 2H2O(l) + O2(g) (using MnO2 as a catalyst).
9. What is the difference between physical and chemical ways of bringing a change?
The main difference is that physical changes do not form new substances, while chemical changes produce new substances with different properties.
- Physical change: Change in state, shape, or size (e.g., melting ice).
- Chemical change: Formation of new products (e.g., rusting — 4Fe(s) + 3O2(g) → 2Fe2O3(s)).
10. Can sound or mechanical action bring about a change in matter?
Yes, mechanical action such as grinding, cutting, or hammering can bring about a physical change by altering size or shape without changing composition.
- Grinding sugar crystals into powder changes particle size only.
- Stretching a metal wire changes its shape but not its chemical formula.
