
the compound H3N:BF3 is isoelectronic with A)B2H6 B)C2H6 C)C5H12 D)C3H6 . PLEASE EXPLAIN. ...

Which of the following is most covalent – ...

25 mL of a 0.107 M H3PO4 was titrated with a 0.115 M solution of a NaOH solution to the end point identified by the colour change of the indicator,bromocrescol green.This required 23.1mL.The titration was repeated using pheno ...

Calculate the percentage of available chlorine in a sample of 3.546 g of bleaching powder which was dissolved in 100 mL of water,25 mL of this solution,on treatment with KI and dilute acid,required 20 mL of 0.125 N sodium thi ...

Which of the following is an expression of ideal gas equation ...

(a)A zinc rod weighing 25.00 g was kept in 100 mL of 1 M CuSO4 solution.After a certain time molarity of Cu2+ in solution was 0.8 M.What was the molarity of the sulphate ion(SO42)?What was the weight of the zinc rod after cl ...

The density of gas A is twice that of B at the same temperature the molecule weight of gas B is thrice that of A. the ratio of pressure of gas A and gas B will be: ...

Which species has the maximum number of lone pair of electrons on the central atom ...

The greatest bond angle is found in ...

The hydrogen bond is strongest in ...

The compound which contains both ionic and covalent bonds is ...

Element X is strongly electropositive and element Y is strongly electronegative. Both are univalent. The compound formed would be ...

The water vapour pressure at 293 K is 2338 Pa and the vapour pressure of an aqueous solution is 2295.8 Pa. Determine its osmotic pressure at 313 Kif the solution density at this temperature is 1.01 g/cc. The molecular weight ...

what is the freezing pt of a aqueous sol. containing 5 % by mass urea,1% by massof KCl and 10% by mass glucose...(kfH20=1.86) a)290.2 K B)285.5K C)169.93K D)250K ...

In a Hatom the energy in the nth orbit is given as En = 13.6/n2 ev . Show that En+1  En = 13.6*2/n3 for large n values How to solve?? ...

Half lihe is independent of the concentration of the reaction....After 10mins vol. of N2 gas is 10l and after complete reaction it is 50l ..hence rate const : a)(2.303/10)log 5 /min b)(2.303/10)log 1.25 c)(2.303/10)log 2 d)(2 ...

Chlorine molecules are 1.0% dissociated at 975 K at a pressure of 1.0 atm(1.0% of the pressure is due to Cl atoms). Cl2→2Cl Calculate Kp and Kc. ...

A sample of 20g of a compound (m.w=120)which is a non electrolyte is dissolved in 10g of ethanol.if the vapour press of the ethanol at the temp. used is 0.250 atm what is the vapour pressure os the ethanol above the sol. ? a) ...

In a reaction NH4NO2 → N2(g) + 2H2O (l) the volume of N2 after 20 mins and after a long time is 40ml and 70ml respectively ...the value of rate const is: a)(1/20)ln(7/4) /min b)(2.303/1200)log(7/3) /sec c)(1/20)log(7/3) /mi ...

given that for a reaction of first order n,the integrated form of the rate equation is : k=(1/t(n1))[1/(Cn1)  1/(C0n1)] where c0 and c are the values of the reactant concentration at the start of time t ...what is the rel ...

In a reaction NH4NO2 → N2(g) + 2H2O (l) the volume of N2 after 20 mins and after a long time is 40ml and 70ml respectively ...the value of rate const is: a)(1/20)ln(7/4) /min b)(2.303/1200)log(7/3) /sec c)(1/20)log(7/3) /mi ...

The pH of a 102 M HCl solution at 250C would be: a. 2 b. 2 c. 0 d. between 0 & 1 Please provide your logic for the answer as well ...

A weak base BOH of concentration 0.02 mole/litre has a pH value of 10.45.If 100 ml of the base is mixed with 10 ml of 0.1 M HCl, what will be the pH of the mixture? ...

The number of waves made by an electron moving in an orbit having maximum quantum number(m)+3 is (a)3 (b)4 (c)5 (d)6 ...

The first ionization energy of H is 21.79x1019J.Calculate the second ionization energy of He atom. (According to me, 2nd I.E of He=E2E∞ =(21.79x1019)x 22/22 0 (E=21.79x1019x z2/n2 ) =21.79x1019J given correct answer i ...

How much ice will separate if a solution containing 25 g ethylene glycol C[2]H[4]OH[2] in 100 g water is cooled by 10 K?(molal depression constant=1.86 for water). ...

A transition of Hatom spectrum has wavelength 1032Ao.Find the transition.(n1 and n2) ...

Calculate the uncertainty in the velocity of a wagon of mass 2000 kg,whose position is known to an accuracy of ±10 metre. ...

How many times does the electrons go round the first Bohr's orbit of hydrogen in one second? ...

Find the volume of CO2 at NTP obtained on heating 10 gm of pure 90 % pure limestone how to proceed? ...