Sodium carbonate (also known as washing soda or soda ash) is a sodium salt of carbonic acid. In domestic use, it is used as a water softener in laundering. It competes with the magnesium and calcium ions in hard water and prevents them from bonding with the detergent being used. Sodium carbonate can be used to remove grease, oil and wine stains.

Correct Option: C

Sodium carbonate (also known as washing soda or soda ash) is a sodium salt of carbonic acid. In domestic use, it is used as a water softener in laundering. It competes with the magnesium and calcium ions in hard water and prevents them from bonding with the detergent being used. Sodium carbonate can be used to remove grease, oil and wine stains.

An alloy is a mixture or metallic solid solution composed of two or more elements. So they are heterogeneous systems. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal (heat treatment) history. Alloys usually have different properties from those of the component elements.

Correct Option: D

An alloy is a mixture or metallic solid solution composed of two or more elements. So they are heterogeneous systems. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal (heat treatment) history. Alloys usually have different properties from those of the component elements.

One of the two chemical methods starts from natural manganese dioxide and converts it using dinitrogen tetroxide and water to manganese nitrate solution. Evaporation of the water leaves the crystalline nitrate salt. At temperatures of 400°C, the salt decomposes, releasing N2O4 and leaving a residue of purified manganese dioxide.

Correct Option: D

One of the two chemical methods starts from natural manganese dioxide and converts it using dinitrogen tetroxide and water to manganese nitrate solution. Evaporation of the water leaves the crystalline nitrate salt. At temperatures of 400°C, the salt decomposes, releasing N2O4 and leaving a residue of purified manganese dioxide.

Chloroform was once a widely used anesthetic. Its vapor depresses the central nervous system of a patient, allowing a doctor to perform various otherwise painful procedures. Chronic chloroform exposure can damage the liver where chloroform is metabolized to phosgene.

Correct Option: C

Chloroform was once a widely used anesthetic. Its vapor depresses the central nervous system of a patient, allowing a doctor to perform various otherwise painful procedures. Chronic chloroform exposure can damage the liver where chloroform is metabolized to phosgene.

Methyl isocyanate is an intermediate chemical in the production of carbamate pesticides. As a highly toxic and irritating material, it is extremely hazardous to human health. It was the principal toxin involved in the Bhopal disaster, which killed nearly 8,000 people initially and approximately 20,000 to 30,000 people in total.

Correct Option: D

Methyl isocyanate is an intermediate chemical in the production of carbamate pesticides. As a highly toxic and irritating material, it is extremely hazardous to human health. It was the principal toxin involved in the Bhopal disaster, which killed nearly 8,000 people initially and approximately 20,000 to 30,000 people in total.