The key difference between qualitative and quantitative analysis in chemistry is that qualitative analysis in chemistry gives the presence or absence of different chemical components in a sample whereas quantitative analysis in chemistry gives the amount of different chemical components present in a given sample.

As can be seen in the above ngram, quantify is more popular than quantitate, but quantitate’s use is not insignificant in proportion. The main difference between the two words is that quantitate is (i.e. can be) used to mean “to perform quantitative analysis upon”, which is not really synonymous with quantify.

Quantitative analysis is any method used for determining the amount of a chemical in a sample. The amount is always expressed as a number with appropriate units. An acid-base titration is an example of quantitative analysis.

Precipitate: In chemistry, a solid formed by a change in a solution, often due to a chemical reaction or change in temperature that decreases solubility of a solid. In meteorology a precipitate is liquid or solid water (rain, snow, etc.) falling from the sky.

Precipitation Reaction Examples in Real Life Magnesium and calcium oxides are generally found in water pipes as precipitates. Formation of kidney stone: The reaction between calcium ions and oxalic acid that are present in food results in calcium oxalate, which is a type of kidney stone.

Precipitates are insoluble ionic solid products of a reaction, formed when certain cations and anions combine in an aqueous solution. The solids produced in precipitate reactions are crystalline solids, and can be suspended throughout the liquid or fall to the bottom of the solution.

When copper reacts with the elements (oxygen, water and carbon dioxide), it turns from its element color of reddish-brown to green. This chemical reaction is hydrated copper carbonate, and a famous example of it is the Statue of Liberty.

Potassium chloride: Makes a purple flame. Magnesium sulfate: Makes a white flame. Copper chloride: Makes a blue flame. Lithium chloride: Makes a pink flame.

A change in which one or more new substances are formed is known as chemical change. For Example, when the iron is exposed to air and moisture, rust formation takes place. The colour of the surface of the iron also changes. Hence, rusting of iron is a chemical change.

Rust is an orange-brown color resembling iron oxide. It is a commonly used color in stage lighting and appears roughly the same color as photographic safelights when used over a standard tungsten light source.

Red and yellow can be mixed to become orange. Adding these primary and secondary colors results in rust. Although traditionally rust is recognized as a reddish color, it can also be brown, orange, yellow and even green in appearance.

Rusting is an oxidation reaction. The iron reacts with water and oxygen to form hydrated iron(III) oxide, which we see as rust. Boiling the water removes the oxygen and the layer of oil prevents it from re-entering. …

Rusting is oxidation of iron or iron objects. It takes place in the presence of air and moisture. It is a slow process. Due to rusting, rust is formed on iron objects. It is a red-orange colored iron oxide which is formed by the oxidation of iron in presence of oxygen and moisture or water.

the red or orange coating that forms on the surface of iron when exposed to air and moisture, consisting chiefly of ferric hydroxide and ferric oxide formed by oxidation.

Rusting of iron is an example of a redox reaction. During rusting, iron combines with oxygen in the presence of water. This is an oxidation reaction where oxygen acts as an oxidising agent.

This phenomenon takes place in the presence of moisture and air. So, the presence of air and water vapor in air are two necessary conditions for the rusting of iron.

Prevention of rusting of iron

1. (1) Rusting of iron can be prevented by painting.
2. (2) Rusting of iron can be prevented by applying grease or oil.
3. (3) Rusting of iron can be prevented by galvanisation.
4. (4) Iron is coated with chromium to prevent rusting.

The presence of water and oxygen is essential for the rusting of iron. Iron does not rust in dry and carbon dioxide free air. Thus, correct option is D.