Chemical reactions and equations

What kind of reaction does milk left at Room temperature during summer show?

Chemical reaction

Explanation - milk left at room temperature, would eventually curdle as lactic acid begans forming. It's irreversible.

What kind of change and iron tawa or a pan or a nail shows when left exposed to humid atmosphere.

Chemical reaction

Explanation -an iron tawa or a fan or a nail left to exposed in the human atmosphere causes corrosion and eventually rusts.

What kind of reaction does grapes getting fermented have?

Chemical reaction

Explanation - Grapes getting fermented are used for making wine they cannot be irreversed.

What kind of reaction does food getting cooked show?

Chemical reaction.

Explanation - . As food gets cooked the colour shape and state changes which causes a chemical reaction.

What kind of reaction does food getting digested in our body show?

Chemical reaction

Explanation-food getting digested is an irreversible reaction therefore it is a chemical reaction.

What kind of reaction is respiration

Chemical reaction.

When can you say a chemical reaction has taken place?

Whenever a chemical change occurs we can save a chemical reaction has taken place. The following are properties of it.

• Change in state

• Change in colour

• Evoluation of gas

• Change in temperature

What is the white powder we get while burning a magnesium ribbon?

Magnesium oxide

How does a magnesium ribbon burns? What does it release while burning?

Magnesium ribbon burns with a white dazzling flame which changes into white powder. It burns in the presence of oxygen.

What does the lhs side of an chemical equation called?

Reactants.

What is the RHS side of a chemical reaction called?

Products

Which element does not lose or gain any electron during a chemical reaction and only shares and Electron which causes it not to have any charge?

Carbon

Why should an equation be always balanced or why should LHS = RHS in a chemical reaction?

Because of law of conservation of mass which states mass can Neither be created nor destroyed in a chemical reaction.

What is the method of balancing an equation called?

The method of balancing an equation is called Hit and trial method where we make trials to balance the equation by using the small whole number coefficient.

State the types of reaction.

There are Four types of chemical reaction-

1. Combination reaction

2. Decomposition reaction

3. Displacement reaction

4. Double displacement reaction

What is a combination reaction?

A reaction where a single product is formed from two or more reactants is called combination reaction.

State of few examples of combination reaction.

• Burning of coal-

• Formation of water from H2 and O2-

What is a exothermic reaction?

Reaction in which heat is released along with the formation of products is called exothermic chemical reaction.

Give examples for exothermic reaction.

• Respiration

• Burning of coal

• Decomposition of vegetable matter into compost.

What is an endothermic reaction

. Reactions in which energy is absorbed is called endothermic reaction.

Give examples for endothermic reaction

• Photosynthesis

• Black and white photography

What is respiration

. During digestion food is broken down into simpler substances from complex substances where carbon hydrides are broken down to form glucose this glucose combines with oxygen in our cells of bodies and provides energy this is called respiration.

What is decomposition reaction

Reaction value observe that a single reactant breaks down or splits to give simpler, one or more products.

What does ferrous sulphate crystals lose when heated also what changes for the same?

If we heat ferrous sulphate crystals the colour Changes also these crystals lose water when heated.

What state ferrous oxide is in? And what state does Sulphur dioxide and Sulphur dioxide are in?

Ferrous oxide is solid in state while sulphur dioxide and sulphur trioxide are gases.

Alcium Oxide is also called _____

Quicklime or lime.

What is used in manufacturing of cement

Alcium Oxide or quick lime

What is the chemical formula of marble

Caco3

What does also called slaked lime

Calcium hydroxide

What is slaked lime used in

Whitewashing walls

Why does solution of slaked lime which is used for whitewashing turns shiny in 3 days of applying?

A solution of slaked lime used for whitewashing which is calcium hydroxide slowly reacts with carbon dioxide in air to form a thin layer of calcium carbonate in walls this calcium carbonate is formed after 2 to 3 days of whitewash which gives a shiny finish to wall

State the types of decomposition reaction.

There are three types of decomposition reaction.

• Thermal decomposition

• Photolytic decomposition

• Electrolytic decomposition

What is thermal decomposition

When a decomposition reaction is carried out by heating it is called thermal decomposition

Give an example for thermal decomposition

When we take about 2 grams of lead nitrate powder in a boiling tube we observe the emission of brown fumes. This brown fumes are nitrogen dioxide as this reaction takes place with presence of heat it is a thermal reaction.

What is photolytic decomposition reaction

Reaction which is carried out due to light energy or sunlight is called photolytic decomposition reaction.

What is an electrolytic decomposition reaction?

A reaction which is carried out by electricity or electric current is called an electrolytic reaction.

What is a displacement reaction

A reaction where more reactive element replaces are less reactive element is called displacement reaction.

What is a double displacement reaction?

Reaction where two elements exchange their ions is called double displacement reaction.

What is an insoluble substance formed called

Precipitate.

Any reaction that produces a precipitate reaction can be called as?

Precipitation reaction

What is oxidation

If a substance gains oxygen during a reaction It is called to be oxidised meaning oxidation reaction has took place.

What is reduction

And reaction where substance loses Oxygen and gains hydrogen is said to be reduced which causes reduction reaction.

What is a r redox reaction

When one reactant gets oxidized while other get reduced during a reaction it is said to be oxidation reduction reaction or redox reaction.

What is corrosion

When a metal is attacked by substances of air such as moisture acids etc it is said to corred and this process is called corrosion

Give example of corrosion

Rusting of iron

In which colour does silver and copper get coated when coroid?

Silver gets coated with black while copper gets coated with green.

What is rancidity

When fats and oils are oxidized they became runs said and their smell and taste change.

What is used to prevent rancidity

Substances which prevent oxidation is called antioxidants. Or keeping food in air tight containers which contains fats and oils helps to slow down oxidation.