Chemistry Quiz 3

The gas used for filling weather balloons is helium. Hydrogen is lighter than air and can be used in filling air balloons but due to its highly inflammable nature, it is not used in air balloons.

Bronze is an alloy traditionally composed of copper and tin. Bronze is typically consists of approximately 88 percent copper and 12 percent tin.

Petrol has the least density among the given liquids. Mercury has a density of 13545.848 kg/m³, which is about 13.5 times denser than water (1000 kg/m³). Water is denser than petrol (800 kg/m³)

Fission reaction produces the most harmful radiation. In nuclear fission reaction, the nucleus of an atom splits into two or more smaller nuclei. The fission process often produces gamma photons and releases a very large amount of energy even by the energetic standards of radioactive decay.

Biological oxygen demand (BOD) generally represents how much oxygen is needed to break down organic matter in water. Clean water has BOD which is less than 5 ppm.

Saccharin (C₇H₅NO₃S) is made up of Toluene (C₇H₈). It is a zero-calorie artificial sweetener. It is about 200-700 times sweeter than sugar and is commonly used to replace it. It is made in a labouratory by oxidizing the chemicals o-toluene sulfonamide or phthalic anhydride.

Candle is a mixture of Paraffin wax and stearic acid. Paraffin wax (C_nH_2n+2) is a white or colourless soft, solid wax. It's made from saturated hydrocarbons. Stearic acid, another name for octadecanoic acid CH₃(CH₂)₁₆COOH, is one of the most common fatty acids.

Sodium is used in the yellow lamps used for street lighting. Sodium-vapour lamps are good for night-time illumination because of their high efficiency and because the light they produce penetrates mist and fog particularly well.

Paraffin wax is a colourless soft, solid wax obtained from petroleum, coal or oil shale. It consists of a mixture of hydrocarbon molecules containing between twenty and forty carbon atoms. It's often used in skin-softening salon and spa treatments on the hands, cuticles, and feet.

Metals are used in crackers like strontium carbonate is used for red fireworks, calcium carbonate is used for orange fireworks, sodium nitrate is used for Yellow fireworks, barium Chloride is used for green fireworks and copper chloride is used for blue Firework.