Chemistry investigat project

2015-2016Made

by : Teju shinde Class : X!!

Acidity in tea.. Tea can be described

as an agricultural plant, that is

industrially important because of

the produce of its leaves, when

immersed in hot water. Tea,

however is an aromatic beverage,

that can be prepared in several

different ways.

Tea Ceremony in Kyoto

Kyoto's Premier Tea Ceremony near Kiyomizu temple

1. Each method of preparation has a certain effect on the acidity of

the beverage Our aim in this experiment is to capture the

difference in the acidity of the beverage by analyzing the

mixture in different ways. Hence, we prepare the beverage in different popular forms, and check its acidity by using a

universal indicator.

Tea, after water, is the world’s most popular beverage of consumption, as it is not

extremely expensive, and has a pleasant texture and aroma.

The leaves of the tea plant (Camelia Sinensis) are oxidized and cured. The leaves are then

introduced into hot/boiling water,

Different Kinds of TeaThere are tens of

hundreds of different species of tea. However, due to unavailability, we can only test a certain limited amount. However, I wish to discuss several popular species and their uses. Normal tea is your everyday garden variety leaf, that has been oxidized and cured into either dark black, lighter black or even white varieties.

 .

This type of tea is usually drunk for the purpose of the drug present in it (the stimulants, ‘Caffeine’ and ‘Theanine) which increases human activity and reduces stress respectively. White Tea: This tea is wilted and the leaves are unoxidized Yellow Tea: This tea is unwilted and unoxidized. The leaves are, however allowed to turn slightly yellow

Green Tea: This tea is also unwilted and unoxidized. It is usually herbal (has herbal additives). Unlike yellow tea, it is not allowed to turn yellow. Oolong Tea: This is traditional Chinese tea. The tea is wilted and bruised and allowed to undergo partial oxidization Black Tea: This tea is wilted, sometimes crushed and generally highly oxidized. This tea is probably the most consumed.

Factors Affecting Tea’s pH Value:-

Tea may be consumed in several different ways. As stated earlier, each method of preparation may impact the acidity and basicity.1. Additives: Additives are elements that are added to tea, after it has been prepared. The addition of additives make tea tastier, healthier, longer lasting, more expensive, etc. and hence alter the pH value2. Oxidation: The levels of oxidation of the leaves also affect pH value. Highly oxidized tea (e.g. black tea) has different acidity compared to unoxidized or lightly oxidized tea (e.g. Green Tea, Oolong Tea).3. Addition of Milk: Milk is a colloid that comprises of lactic acid, and hence is responsible for an increase in acidity in tea.

Addition of Sugar: Sugar is also responsible for the change in pH value in

beverages, as we will find experimentally

5. Type of Water: Boiled tap water in Kathmandu

compared to Filtered Water and water that

has undergone “Reverse Osmosis” also has different pH levels.

ConclusionTea can be described as an agricultural plant, that is

industrially important because of the produce of its leaves,

when immersed in hot water. Tea, however is an aromatic

beverage, that can be prepared in several different ways. Each method of preparation has a

certain effect on the acidity of the beverage