--%>
Assignment Help - homework help

Determining concentration in ppm

A 500 gm tooth paste sample has 0.2g fluoride concentration. Determine the concentration of F in terms of ppm level: (a) 250 (b) 200 (c) 400 (d) 1000

Answer: (c) F-ions in ppm = (0.2/500) x 106 = 400

   Related Questions in Chemistry

  • Q : What are biodegradable polymers?

      These are polymers that can be broken into small segments by enzyme-catalysed reactions. The required enzymes are produced by microorganism. It is a known fact that the carbon-carbon bonds of chain growth polymers are inert to enzyme-catalysed reactions, and hence they are non biod

    		•
  • Q : Vapour pressure of methanol in water

    Give me answer of this question. An aqueous solution of methanol in water has vapour pressure: (a) Equal to that of water (b) Equal to that of methanol (c) More than that of water (d) Less than that of water

    		•
  • Q : Structure of a DNA molecule Elaborate

    Elaborate the structure of a DNA molecule?

    		•
  • Q : Explain solid in liquid solutions. The

    The French chemist Francois Marie Raoult (1886) carried out a series of experiments to study the vapour pressure of a number of binary solutions. On the basis of the results of the experiments, he proposed a generalization called Raoult's law which states that, <

    		•
  • Q : Problem on endothermic or exothermic At

    At low temperatures, mixtures of water and methane can form a hydrate (i.e. a solid containing trapped methane). Hydrates are potentially a very large source of underground trapped methane in the pole regions but are a nuisance when they form in pipelines and block th

    		•
  • Q : Depression in the freezing point When

    When 0.01 mole of sugar is dissolved in 100g of a solvent, the depression in freezing point is 0.40o. When 0.03 mole of glucose is dissolved in 50g of the same solvent, depression in the freezing point will be:(a) 0.60o  (b) 0.80o

    		•
  • Q : Statement of Henry law Determine the

    Determine the correct regarding Henry’s law: (1) The gas is in contact with the liquid must behave as an ideal gas (2) There must not be any chemical interaction among the gas and liquid (3) The pressure applied must be high (4) All of these.

    		•
  • Q : Define tripod and its use Illustrate a

    Illustrate a tripod? And how it’s used?

    		•
  • Q : Problem on decomposition reaction

    Nitrogen tetroxide (melting point: -11.2°C, normal boiling point 21.15°C) decomposes into nitrogen dioxide according to the following reaction: N2O4(g) ↔ 2 NO2(g)<

    		•
  • Q : Problem on molecular weight of solid

    The vapor pressure of pure benzene at a certain temperature is 200 mm Hg. At the same temperature the vapor pressure of a solution containing 2g of non-volatile non-electrolyte solid in 78g of benzene is 195 mm Hg. What is the molecular weight of solid: