PREFIXES The International System of Units (SI) specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol. The SI prefixes are standardized by the International Bureau of Weights and Measures. S.I PREFIXES FACTOR PREFIX SYMBOL FACTOR PREFIX SYMBOL 10 24 =(10 3 ) 8 yotta Y 10 -1 Deci d 10 21 =(10 3 ) 7 zetta Z 10 -2 centi c 10 18 =(10 3 ) 6 exa E 10 -3 =(10 3 ) -1 milli m 10 15 =(10 3 ) 5 peta P 10 -6 =(10 3 ) -2 micro m 10 12 =(10 3 ) 4 tera T 10 -9 =(10 3 ) -3 nano n 10 9 =(10 3 ) 3 giga G 10 -12 =(10 3 ) -4 pico p 10 6 =(10 3 ) 2 mega M 10 -15 =(10 3 ) -5 femto f 10 3 =(10 3 ) 1 kilo k 10 -18 =(10 3 ) -6 atto A 10 2 hecto h 10 -21 =(10 3 ) -7 zepto Z 10 1 deka da 10 -24 =(10 3 )...
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CONCENTRATION UNITS OF SOLUTIONS There are various types of concentration units of solutions. They are as following: (1) Percentage composition (2) Molarity (M) (3) Molality (m) (4) Normality (N) (5) Mole fraction (X) (6) Parts per million (ppm) (1) PERCENTAGE COMPOSITION The parts of solute dissolved in 100 parts of solution is called percentage composition of solution. The amounts of solute and solvent can be expressed in percentage composition by four different ways. (a) Percentage weight / weight (b) Percentage weight / volume (c) Percentage volume / weight (d) Percentage volume / volume. (a) Percentage Weight / Weight: It is the weight of a solute dissolved per 100 parts by weight of solution. or number of grams of solute dissolved per 100g of solution is called %W/W. Example: 5% w/w sugar solution means 5 g of sugar is dissolved in 95g of solvent say water. Total mass of solution is 100 g. Formula: % by weight ...