Periodic Properties

Q.

Which of the following indicates the correct order of acidic strength of the following acids.

I. HCOOH (Ka = 1.8 $\times$ ${10}^{-4}$)

II. $C{H}_{3}COOH$(Ka = 1.8 $\times$ ${10}^{-5}$)

III : HCN (Ka = 4.8 $\times$ ${10}^{-10}$)

IV: HS- (Ka = 1 $\times$10-14)

1. I > II > III > IV

2. IV > III > II > I

3. I > III > II > IV

4. II > III < I < IV

Q. 7. arrange the following in order of thier decreasing relative reactivity with an electrophile- toluene, p- nitrotoluene, 1, 4-dinitrobenzene

Q. 38. Which of the following statement is incorrect? (1) Al2O3 cannot be reduced into Al by Cr2O3 (2) Ca is stronger reducing agent than Mg (3) At 673 K, CO is poor reducing agent than carbon (4) All of these

Q. explanation of line spectrum of hydrogen

Q.

Which of the following is a pale yellow-green gas at room temperature?

1. Chlorine

2. Bromine

3. Iodine

4. None of the above

Q. what is the difference between oxidation number, covalency and coordination number ?

Q. 16. What is producer and water gas? Explain how they made?

Q. If we consider H2/Cl2 molecule is its heat of atomization and bond dissociation energy the same ? reaction is same for atomization and bond dissociation : H2 (g) → 2H (g)

Q. Electronegativity of fluorine is greater than that of chlorine but electron affinity of chlorine is greater than that of fluorine.

1. False
2. True

Q. 15. What is hydrogen spectrum

Q. How to find relative reactivity order? In a compound how to find the number of identical hydrogen?

Q. Which of the following represents the correct order for acidic strength:

1. $HCl{O}_4>HI{O}_4>HBr{O}_4$
2. $HCl{O}_4>HBr{O}_4>HI{O}_4$
3. $HCl{O}_4<HBr{O}_4>HI{O}_4$
4. None of these

Q. Which among the following is the most reactive?

1. $C{l}_2$
2. $B{r}_2$
3. $I_2$
4. $ICl$

Q. Oxidizing action increases in the following order:

1. $Cl<Br<I<F$
2. $Cl<I<Br<F$
3. $I<F<Cl<Br$
4. $I<Br<Cl<F$

Q.

Which of the following is a pale yellow-green gas at room temperature?

1. Chlorine

2. Bromine

3. Iodine

4. None of the above

Q. Formation of arenium ion is the slowest step in the sulphonation of benzene and it is a reversible rection.

1. True
2. False

Q. Formation of arenium ion is the slowest step in the sulphonation of benzene and it is a reversible rection.

1. True
2. False

Q. A mixture of feo and fe3o4 when heated in air to a constant weight gains 5% in weight. Find the composition of the initial mixture. ( Using Principle of Atom Conservation method)