The red colour of blood is due to a compound called "haemoglobin". It contains 0.335 % of iron. Four atoms of iron are present in one molecule of haemoglobin. What is its molecular weight? (At. mass : Fe 55.84)

Haemoglobin contains 0.33% of iron by weight. The molecular weight of haemoglobin is approximately 67200. The number of iron atoms. (At wt of Fe=56) present in one molecule of haemoglobin is

Carbon forms a large number of compounds because of its two unique properties formed many have long straight chains of carbon, branched chains of carbon or rings of carbon. In these compounds, carbon atoms may form single, double or triple covalent bonds. Compounds in which the carbon atoms are linked to each other by single bonds are called saturated carbon compounds whereas compounds having at least one carbon-carbon double or triple bond are called unsaturated carbon compounds. Compounds containing only carbon and hydrogen are known as hydrocarbons. Based on the above information, answer the following questions. v. What is common name and molecular formula of ethyne?

Metals get attacked by substances around it such as moisture, acids, etc. Metal is said to 'corrode' due to this attack and the process is called corrosion. Many metals like iron, copper, silver, etc. get corroded. When iron is exposed to moist air, it undergoes corrosion and a reddish brown coloured solid layer is formed on its surface. Corrosion of iron, which is known as rusting, is a serious problem as enormous amount of money is spent every year to replace damaged iron. Similarly, copper reacts with moisture and. CO_(2) in air to form a green coloured coating of basic copper carbonate on its surface. Silver acquires a black colour when exposed to air containing H_(2)S due to the formation of silver sulphide on its surface. Based on the above paragraph, answer the following question. What happens to silver ornaments if they are exposed to air containing H_(2)S gas?

Metals get attacked by substances around it such as moisture, acids, etc. Metal is said to 'corrode' due to this attack and the process is called corrosion. Many metals like iron, copper, silver, etc. get corroded. When iron is exposed to moist air, it undergoes corrosion and a reddish brown coloured solid layer is formed on its surface. Corrosion of iron, which is known as rusting, is a serious problem as enormous amount of money is spent every year to replace damaged iron. Similarly, copper reacts with moisture and. CO_(2) in air to form a green coloured coating of basic copper carbonate on its surface. Silver acquires a black colour when exposed to air containing H_(2)S due to the formation of silver sulphide on its surface. Based on the above paragraph, answer the following question. What is rust?