Monday, April 27, 2009

How anti dandruff shampoo works

Anti dandruff shampoo works in three way.

1. Ingredient such as coal tar are antikeratostatic, inhibits keratinocyte cell division.

2. Detergent of shampoo are keratolytic which breaks the accumulation of scale.

3. Anti fungal agent such as ketoconazole inhibit the growth of yeast.

Sunday, April 26, 2009

Why only female mosquitoes are bite

Female mosquitoes actively search for a blood meal as she needs the protein in the animals , humans blood to produce yolk for her fertilised eggs. The yolk provides the nutrients for her young.

Friday, April 24, 2009

Apple turn brown on being cut

Apple contains iron in the form of ferrous ions. These ferrous ions easily oxidise into ferric ions by air, which are in brown color, when the apple is cut, the ferrous ions of the surface oxidises to ferric ions hence brown.

Thursday, April 23, 2009

How pain balm works

Pain balms generally contain 3 components i.e methyl salicylate,menthol and camphor. When balm applied, salicylate absorbed through the skin and acts as an analgesic, menthol dilates the blood vessels. Because of the increased blood flow one gets a cool sensation in the balm applied area. This is useful in case of headache and rheumatic pains. Camphor also acts as rubefacient and mild analgesic.

Tuesday, April 21, 2009

Sound when thumb and middle finger are clicked

A small amount of air is trapped and pressurised when the fixed end of the thumb and the free end of the middle finger are brought together. When this pressurised air is relased suddenly during the clicking it produces a sound.

Saturday, April 18, 2009

Lemon drops create white spots on the floor

Citric acid of lime juice react with calcium silicates and calcium aluminates of cement on the floor, forms calcium citrate which gives a white color.

Thursday, April 16, 2009

Testing of purity of Honey

Method 1: Aniline chloride test
To a small quantity of honey add few drops of aniline chloride with stirring. Appearance of crimson red color indicates adulteration.

Method 2: Granulation

Honey subjected to cool weather conditions, it granulated as sugar which is main constituent of honey. As these crystals subjected to hot water it attains normal liquid state shows, no adulteration.

Method 3: Solubility

Pure honey does not dissolve in water. Thus easily finds adulteration.

Wednesday, April 15, 2009

why does water taste sweet when had after a gooseberry

Amla (Indian gooseberry) is a natural rich source of vitamin C which gets oxidised easily. The fruit contains 28 % of tannin which prevents this oxidation. When hydrolysed, tannin gives Gallic acid, Ellagic acid and Glucose which is sweet. As the disslution of glucose is an endothermic reaction a cooling effect is produced.

Tuesday, April 14, 2009

Musty odour after shower

The peculiear smell immediately after a shower is due to certain volatile chemical compounds released by a group of soil-inhibiting bacteria called streptomycete. These streptomycetes grouped as actinomycetes and are abundant in dry warm soil. when wetted by rain after a long dry spell, the streptomycetes release compounds such as geosmin and 2-methyl- isoborneol . This is the reason, why we get the musty odour only after the first rain of the rainy season.

How does water cool in a mud pot

By the phenomenon of Evaporative cooling, water remains cool in a mud pot. As the pot made up with mud it has number of very minute pores, through which water can slowly ooze out. Thus these pores increase the surface area of water and consequently increases evaporation. For the evaporation of water, it requires some energy which is takes as heat from the water itself. This results in lowering the temperature of the water in the mud pot.

Friday, April 10, 2009

Water Test

CuSO4.5H2O is blue color chemical, on dehydration it looses its color and called as anhydrous copper sulphate. By adding this to the solutions only water forms blue color.
Guess it ! what Happens?



Yes exactly! whenever anhydrous CuSO4 added to water, it hydrated and turns to original color.