NCERT 2022 | जीव जगत का वर्गीकरण - L2 | Biological Classification | Hindi Medium | Pooja Ma'm |10 AM

When 10mL of an aqueous solution of KMnO_(4) was titrated in acidic medium , equal volume of 0.1M of an aqueous solution of ferrous sulphate was required for complete discharge of colour. The strength of KMnO_(4) in grams per litre is ___________ xx10^(-2) . (Nearest integer) [Atomic mass of K=39, Mn=55, O=16]

A small coil C with N = 100 turns is mounted on one end of a balance beam and introduced between the poles of an electromagnet as shown in the figure. The cross-sectional area of coil is A = 1.0 cm^(2) , length of arm OA of the balance beam is l = 20 cm. When there is no current in the coil, the balance is in equilibrium. On passing a current i = 18 mA through the coil, the equilibrium is restored by putting the additional counter weight of mass Delta m = 40 mg on the balance pan. Find the magnetic induction at the spot where coil is located.

A small coil C with N=200 turns is mounted on one end of a balance beam and introduced between the poles of an electromagnetic as shown in Fig. The area of the coils is S=1cm^2 , the length of the right arm of the balance beam is l=30cm. When there is no current in the coil the balance is in equilibrium. On passing is a currentI=22mA through the coil, equilibrium is restored by putting an additional weight of mass m=60mg on the balance pan. Find the magnetic induction field (in terms of x 10^-1T ) between the poles of the electromagnetic assuming it to be uniform.

The colloidal particles are electrically charged as a indicated by their migration towards cathode or anode under the applied electric field. In a particular colloidal system, all particles carry either positive charge or negative charge. The electric charge on colloidal particles orginate in several ways. According to preferential adsorption theory, the freshly obtained precipitate particles adsorb ions from the dispersion medium, which are common to their lattice and acquire the charge of adsorbed ions. For example, For example, freshly obtained Fe(OH)_(3) precipitated is dispersed, by a little FeCl_(3) , into colloidal solution owing to the adsorption of Fe^(3+) ions in preference. Thus sol particles will be positively charged. In some cases the colloidal particles are aggregates of cations or anions having ampiphilic character. When the ions posses hydrophobic part (hydrocarbon end) as well as hydrophilic part (polar end group), they undergo association in aqueous solution to form particles having colloidal size. The formation of such particles, called micelles plays a very important role in the solubilization of water insoluble substances, (hydrocarbon, oils, fats, grease etc.). In micelles, the polar end groups are directed towards water and the hydrocarbon ends into the centre. The charge on sol particles of proteins depends on the pH. At low pH, the basic group of protein molecule is ionized (protonated) and at higher pH (alkaline medium), the acidic group is ionized. At isoelectric pH, characteristic to the protein, both basix and acidic groups are equally ionized. The stability of colloidal solution is attributed largely to the electric charge of the dispersed particles. This charge causes them to be coagulated or precipitated. On addition of small amount of electrolytes, the ions carrying oppiste charge are adsorbed by sol particles resulting in the neutralization of their charge. When the sol particles either with no charge or reduced charge, come closer due to Brownian movement, they coalesce to form bigger particles resulting in their separation from the dispersion medium. This is what is called coagulating or precipitation of the colloidal solution. The coagulating power of the effective ion, which depend on its charge, is expressed in terms of its coagulating value, defined as its minimum concentration (m mol/L) needed to precipitate a given sol. When 9.0 ml of arsenious sulphide sol and 1.0 ml of 1.0 xx 10^(-4) M BaCl_(2) are mixed, turbidity due to precipitation just appears after 2 hours. The effective ion and its coagulating value are respectively :

Calculate the pH at which the following reaction will be at equilibrium in basic medium : A_(2)(s) hArr A^(-)(aq) +AO_(3)^(-) (aq) When the equilibrium concentration at 300 K are: [A^(-)] = 0.1M, [AO_(3)^(-)] = 0.1M Given: DeltaG_(f)^(@) of OH^(-)(aq) =- 150 kJ//"mole" , DeltaG_(f)^(@) "of" H_(2)O(l) =- 233 kJ//"mole" DeltaG_(f)^(@) "of" A^(-)(aq) =- 50 kJ//"mole" , DeltaG_(f)^(@) "of" AO_(3)^(-) (aq) =- 123.5 kJ//"mole" , R = (25)/(3) J "mole"^(-1) K^(-1), log_(e) 10 = 2.3

A small coil C with N = 200 turns is mounted on one end of a balance beam and introduced between the poles of an electromagnet as shown in Fig. The cross sectinal area of the coil is S = 1.0 cm^(2) , the length of the arm OA of the balance beam is l = 30 cm . When there is no current in the coil the balance is irl equilibrium. On passing a current I = 22 mA through the coil the equiibrium is restroed by putting the additional counterweight of mass Delta m = 60 mg ont he balnace pan. Find the magnetic induction at the spot where the coil is located.

Copper pyrites, CuFeS_(2) , is the important source of copper 10 gm of it was leached with dil. H_(2)SO_(4) and solution diluted to 1L. 10 mL of this solution required 10 mL of 0.02 M KMnO_(4) is acidic medium. What is the % of Fe in copper pyrite.

A secondary alkyl halide (A) hydrolyzes with alkali (B) in aqueous medium ismultaneously via S_(N)1 and S_(N)2 pathways with rate constants k_(1) and k_(2) , respectively. form kinetic data, it was found that a plot of = (-1)/([A])(d[A])/(dt) vs [B] is straight line with a slope equal to 2.7 xx 10^(-4) L mol^(-1) min^(-1) and intercept equal to 1.02 xx 10^(-3) . Minimum initial concentration of [A] = 0.2 M and [B] , i.e., [overset(ɵ)(OH)] = 0.5 M . The initial rate of consumption is isopropyl chloride (in M min^(-1)) is