water added to sand and salt is a physical change, while added cement is a chemical change justifies - Chemistry - Changes around us - 6025338 (2023)

FAQs

Is mixing sand and salt a physical change or chemical change? ›

Simply mixing two substances to form a mixture, such as the mixing of sand and salt, is another example of a physical change.

Addition of water to salt or sand is a physical change whereas to cement is a chemical change. Justify the statement. The addition of water to salt or sand is a physical change because the process can be reversed by using physical methods of separation. in the case of sugar and filtration in the case of sand.

Answer: Solution: When water is added to sodium chloride, there is no new product formed, hence it is a physical change.

Water combines with cement to form a paste that binds it together. This paste is altogether a new substance and we can not get back cement and water from the mixture. Therefore, it is an irreversible chemical change.

When water is added to mixture of sand and salt a solution is formed in which salt get dissolved and sand remain as such. This is a physical change as we get back salt and sand from solution by filtration followed by evaporation.

Therefore, dissolving salt in water is an example of a chemical change.

The making of concrete is a very complex process involving both chemical and physical changes.

Both salt and sand will dissolve completely in water.

Answer: Some examples of physical changes are: Melting an ice cube. Boiling water. Mixing sand and water.

Reaction of sodium with water

Sodium metal reacts rapidly with water to form a colourless solution of sodium hydroxide (NaOH) and hydrogen gas (H₂). The resulting solution is basic because of the dissolved hydroxide. The reaction is exothermic.

What happens when cement and water are mixed? ›

When water is added to cement, the chemical reaction called hydration takes place and contributes to the final concrete product. The calcium silicates contribute most to the strength of concrete. Tricalcium silicates are responsible for most of the early strength (first seven days).

When water is added to cement, heat is generated as an end product. It is an exothermic reaction heat, which is a reaction that emits heat. The chemical change that occurs is non-reversible which is why we find it very difficult to reuse cement and concrete.

Is mixing cement a chemical or physical change? After mixing cement and water , it is not possible to get water and cement separately. Also the properties of cement is changed . So this is a chemical reaction.

When salt is mixed with water, the salt dissolves because the covalent bonds of water are stronger than the ionic bonds in the salt molecules.

Separating a mixture is an example of a physical change. There are several ways to separate a mixture. The use of one's hands in pulling the parts of a mixture apart is one example. Filtration is another way to separate mixtures.

The two compounds, water, and salt, are combined uniformly in seawater. These compounds can be separated by the physical process of evaporation. Therefore, seawater is a mixture.

Mixing sand and water is not a chemical reaction but is simply the creation of a mixture. Sand and water have no reactivity toward each other, and so when mixed, they form a mixture in which the sand sinks to the bottom of the water.

As we can see that the process of obtaining salt by the evaporation of seawater is a process of crystallization which is a reversible process and a physical change, these crystals will convert again in salt solution (seawater) by dissolving them in water. Thus it is a physical change.

Mixing of salt in water is a reversible change.

Breaking up concrete is a physical change. Sand being washed out to sea from the beach is a chemical change. When ice cream melts, a chemical change occurs. Acid rain damaging a marble statue is a physical change.

What is the chemical reaction of cement? ›

The lime reacts with silicon dioxide to produce dicalcium silicate and tricalcium silicate. The lime also reacts with aluminium oxide to form tricalcium aluminate. In the last step, calcium oxide, aluminium oxide, and ferric oxide react together to form cement.

Burning, cooking, rusting and rotting are examples of chemical changes.

Saltwater acts as if it were a single substance even though it contains two substances—salt and water. Saltwater is a homogeneous mixture, or a solution.

If you have a mixture of salt and sand, then by placing the mixture in water, salt dissolves but the sand remains. When this new mixture is then filtered, the salt in the salty water solution passes through the filter paper to form the filtrate and the sand remains as the residue.

The dissolving of the Kool-Aid powder into water is a physical change. The powder, the solute, is dissolved in water, the solute, forming a Kool-Aid solution.

Ripping, tearing, smashing, stirring, squishing, and changing the shape of a substance by mixing it with another is called a physical change. Chemical changes occur when a new, third substance is created by combining two substances.

False, It is a reversible change because you can remove sand from the water sand mixture by filteration.

Combine sand, cement and water to make a mortar and to make concrete, add aggregates to the mix.

Concrete: Concrete is a composite material which is composed of coarse and fine aggregate bounded together with cement paste and mixed with water that hardens with time. Also used sometimes with other hydraulic cements like with Portland cement to form Portland cement concrete.

Initial after mixing the cement and water comes into contact with each other, a peak in temperature happens. The aluminate (C3A) reacts with H2O (Calcium and sulfate ions) to form ettringite (aluminate hydrate).

Is addition of water to cement a reversible change? ›

Mixing cement with water is an irreversible change.

Dissolving and mixing:

Simple forms of dissolving and mixing are considered physical changes, but mixing the ingredients of a cake is not a simple mixing process.

Cement when comes in contact with moisture it gets hardened. It cannot be converted back to the powdered cement again. Hence, it is a permanent change.

Hardening of cement is a physical change.

For example salt dissolving in water is usually considered to be a physical change, however the chemical species in salt solution (hydrated sodium and chlorine ions) are different from the species in solid salt.

Salt is water soluble, while sand is not. This means the two can be mixed in water and stirred. The salt will dissolve and the sand will not. These differences form the basis for separation of the three materials.

No, mixing salt and sugar is not a chemical reaction.

On the other hand, physical reactions are the result of molecular rearrangement to result in a change in the physical properties of substances.

For example, chopping up a carrot or ice melting into water are both physical changes. Chemical changes are those where one or more substances are combined to produce a new substance. At the end of a chemical change, you have a new substance. Burning a piece of paper would be a chemical change, as would baking a cake.

Salt is soluble in water, which would give a homogeneous mixture. But, when we take sand, which is insoluble, we will have a mixture of two different phases, a solid and a liquid, therefore this is a heterogeneous mixture.

A mixture of sand and salt is a heterogeneous mixture. Suggest Corrections. 3. Similar questions.

What mixture is sand and salt? ›

The mixture of salt and sand is an example of heterogenous mixture as both components can be seen by naked eyes and easily separated.

Therefore, the dissolving of salt in water is a reversible change.

The melting of ice is a physical change when it occurs naturally. But when you speed up the process by using a reactant, such as salt, it becomes a chemical reaction.

In a physical change, no new substance is formed. A chemical change is always accompanied by one or more new substance(s). Physical change is easily reversible i.e original substance can be recovered. Chemical changes are irreversible i.e. original substance cannot be recovered.

Sugar dissolving in water is a physical change. The sugar can be obtained back by evaporation of water and the water by condensation of water vapour.

The dissolution of salt in water is the process of dissolving salt in water. It is a physical change as no new substance is formed and, the salt can be recovered back on evaporation of water.

Dissolving sugar in water is a physical change because sugar molecules are dispersed, but the individual sugar molecules are unchanged or do not undergo any chemical change.