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An aqueous solution of 2% non-volatile solute exerts a pressure of 1.004 bar at the normal boiling point of the solvent. What is the molar mass of the solute?
Solution :
 Given values
Concentration is given in percent so that take
mass of the solution = 100 g
mass of non-volatile solute = 2% = 2g mass of the solvent = (100 — 2) = 98 g molecular mass of solvent (water) = 18
We have to find molecular mass of solute
The vapour pressure of pure boiling water = 1atm = 1.013 bar.
Change in vapour pressure  = (1.013 — 1.004) = 0.009 bar
Formula of Raoult’s lawHere n1 and n2 are the number of moles of solvent and solute respectively present in the solution. For dilute solutions n2 <>< n1, hence=”” neglecting n2=”” in=”” the=”” denominator=”” we=””> n1,>
Use this formula we get 
Here w1 and w2 are the masses andM1 and M2 are the molar masses of the solvent and solute respectively.Plug the values in above formula we get 
Cross multiply we get 
What is the order of the reaction with respect to A and B?
Let the order of reactant A = x
And the order of reactant B = y
We have the formula

Take log both side we get
log 2.821 = log 2x
take the log of 2.821 and Use formula log ax= x log a we get
0.4504 = x log 2
Value of log 2 = 0.3020
We get
x = 0.4504/0.3020 = 1.5(approx)
The order of reactant A = 1.5
The order of reactant B = 0  @2manufacture of sulphuric acid IntroductionIt was once said that a country’s wealth could be measured by its production of sulfuric acid (H2SO4). That may no longer be true, but the acid is still used in the manufacture of paints, fertilizers, plastics, fabrics, dyes, detergents, and many other useful products. In this unit you can find out how we make the acid in industry.
The Contact processThe most important process for making sulfuric 
acid in industry is the Contact process. We can think of the Contact process as involving three stages. Look at the process shown in Fig.1 below:
Stage 1Sulfur is imported from Poland or the USA. We can also obtain sulfur from the impurities in fossil fuels such as coal. In the first stage of the process, sulfur is burned in air to make sulfur dioxide gas:sulfur  +  oxygen  arrow.png  sulfur dioxide
S(l)  +  O2(g)  arrow.png  SO2(g)
Stage 2In the next stage, we convert the sulfur dioxide to sulfur trioxide:sulfur dioxide  +  oxygen  eqarrow.png  sulfur 2 SO2(g)  +  O2(g)  eqarrow.png  2 SO3(g)
trioxide The reaction happens on a 
catalyst of vanadium(V) oxide to speed up the reaction. As much sulfur dioxide as possible is changed into sulfur trioxide, and releases of sulfur dioxide are prevented because it is a gas that caus acid raine

the group 17 elements include fluorine(F), chlorine(Cl), bromine(Br), iodine(I) and astatine(At) from the top to the bottom. They are called “halogens” because they give salts when they react with metals. So, now you know what halogens are. Let’s now look at the electronic configuration of these elements.Atomic Properties Let us now look at the various atomic properties of the group 17 elements. We will speak about the ionic and atomic radii, ionization enthalpy and more.Ionisation EnthalpyThese elements have higher ionization enthalpy. This value keeps on diminishing as we move down the group. This happens because of the increase in the size of the nucleus. However, it is interesting to note that fluorine has the highest ionization enthalpy than any other halogen, thanks to its minute size!Electron Gain EnthalpyThe electron gain enthalpy of these elements becomes less negative upon moving down the group. Fluorine has lesser enthalpy than chlorine. We can attribute it to the small size and the smaller 2p sub-shell of the atom of fluorine oxidation The halogens are located on the left of the noble gases on the periodic table. These five toxic, non-metallic elements make up Group 17 of the periodic table and consist of: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). Although astatine is radioactive and only has short-lived isotopes, it behaves similar to iodine and is often included in the halogen group. Because the halogen elements have seven valence electrons, they only require one additional electron to form a full octet. This characteristic makes them more reactive than other non-metal groups.FriedelCrafts reactions The FriedelCrafts reactions are a set of reactionsdeveloped by Charles Friedel and James Crafts in 1877 to attach substituents to an aromatic ring.FriedelCrafts reactions are of two main types: alkylation reactions and acylation reactions. Both proceed by electrophilic aromatic substitution.Image result for friedel crafts reaction

Clemmensen reductionis a chemical reaction described as areductionof ketones (or aldehydes) to alkanes using zinc amalgam and concentrated hydrochloric acid. This reaction is named after Erik ChristianClemmensen, a Danish chemist.Image result for clemmensen reductionSandmeyer reaction

The Sandmeyer reaction is a chemical reactionused to synthesize aryl halides from aryl diazonium salts using copper salts as reagents or catalysts. It is an example of a radical-nucleophilic aromatic substitution.