Friday, October 2, 2009

chemistry questions answer

1. what is density ?
Ans. The density of a material is defined as its mass per unit volume. The symbol of density is ρ

\rho = \frac{m}{V} \,
where:
ρ (rho) is the density,
m is the mass,
V is the volume
2.what is viscosity?
Ans. Viscosity is a measure of the resistance of a fluid which is being deformed by either shear stress or extensional stress. In everyday terms (and for fluids only), viscosity is "thickness." Thus, water is "thin," having a lower viscosity, while honey is "thick" having a higher viscosity. Viscosity describes a fluid's internal resistance to flow and may be thought of as a measure of fluid friction.
3. what is titration?
Ans. Titration is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of a known reactant. Because volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant or titrator, of a known concentration (a standard solutio) and volume is used to react with a solution of the analyte or titrand, whose concentration is not known. Using a calibrated burette to add the titrant, it is possible to determine the exact amount that has been consumed when the endpoint is reached. The endpoint is the point at which the titration is complete, as determined by an indicator (see below). This is ideally the same volume as the equivalence point—the volume of added titrant at which the number of moles of titrant is equal to the number of moles of analyte, or some multiple thereof (as in polyprotic acids). In the classic strong acid-strong base titration, the endpoint of a titration is the point at which the pH of the reactant is just about equal to 7, and often when the solution permanently changes color due to an indicator. There are however many different types of titrations
4. how many type of titration ?
Ans. Acid-base titrations,Redox titrations,Complexometric titrations, zeta potential titration
5. how to use Air Operated Valve in industries?
Ans. An Air Operated Valve is a type of power operated valve that uses air pressure against a piston or diaphragm to produce linear or circular movement to operate a valve
6.what is catalyst ? how many type of catalyst?
Ans. Catalysis is the process in which the rate of a chemical reaction is either increased or decreased by means of a chemical substance known as a catalyst.
there are four type of catalyst
1-Heterogeneous catalysts
2-Homogeneous catalysts
3-Electrocatalysts
4-Organocatalysis
7.which is more chill in 0 degree temperature water or ice ?
Ans. ice

8.what is boiling point?
Ans. The boiling point of an element or a substance is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid. A liquid in a vacuum environment has a lower boiling point than when the liquid is at atmospheric pressure. A liquid in a high pressure environment has a higher boiling point than when the liquid is at atmospheric pressure. In other words, the boiling point of liquids varies with and depends upon the surrounding environmental pressure. Different liquids boil at different temperatures.

9.what is melting point?

Ans. The melting point of a solid is the temperature range at which it changes state from solid to liquid

10.what is normality and how to measure?
Ans.between the concentrations of the various ionic species in a solution. For example, in a salt such as MgCl2, there are two moles of Cl- for every mole of Mg2+, so the concentration of Cl- is said to be 2 N (read: "two normal"). Further examples are given below. It may also refer to the concentration of a solute in any solution. The normality of a solution is the number of gram equivalent weight of a solute per litre of its solution. For example hydrochloric acid(HCl). One litre of aqueous solution of HCl acid contains 36.5 grams HCl. It is called 1N (one normal)solution of HCl. It is given by the following formula:


 \mbox{normality, } N =\left ( \frac{\mathrm{gram\ equivalents}}{\mathrm{liters\ solution}} \right )