List of top Chemistry Questions

Following statements regarding the periodic trends of chemical reactivity of the alkali metals and the halogens are given. Which of these statements gives the correct picture ?

When oxyhaemoglobin changes to de-oxyhaenioglobin, $Fe^{2+}$ ion changes from

The order of electron affinity of halogens is

Electrolysis of dilute aqueous $NaCl$ solution was carried out by passing $10\, mA$ current. The time required to liberate $0.01\, mole$ of $H_2$ gas at the cathode is $(1 \,F\,= 96500 \,C \,mol^{-1})$

The correct statement(s) about the compound given below is/are

What is the equilibrium expression for the reaction, $ {{P}_{4}}(s)+5{{O}_{2}}(g) \rightleftharpoons {{P}_{4}}{{O}_{10}}(s)? $

The enthalpies of combustion of carbon and carbon monoxide are $ -393.5 $ and $ -283\,\text{kJ}\,\text{mo}{{\text{l}}^{-1}} $ respectively. The enthalpy of formation of carbon monoxide per mol is

The volumes of two $ \text{HCl} $ solutions A(0.5 N) and B(0.1 N) to be mixed for preparing 2 L of 0.2 N HCl solution are

When 0.1 mole of an acid is added to 2 L of a buffer solution, the pH of the buffer decreases by 0.5. The buffer capacity of the solution is

Which one of the following reactions is an example of auto-catalysis?

AB is an ionic solid. If the ratio of ionic radii of $ {{\text{A}}^{\text{+}}} $ and $ {{\text{B}}^{-}} $ is 0.52, what is the coordination number of $ {{\text{B}}^{-}} $ ?

Which one of the following reactions occur at the cathode?

Unusual high boiling point of water is result of

The electronic configuration $1 s^{2},\, 2 s^{2} 2 p^{6},\, 3 s^{2} 3 p^{6} 3 d^{9}$ represents a

For the reaction : $ \ce{H_2 +I_2 -> 2HI} $ , the differential rate law is

Benzoylation of phenol in alkaline medium is known as

Addition of sodium acetate to $0.1 \,M$ acetic acid will cause

The $IUPAC$ name of $CH_{3}-CH=CH-C \equiv CH$ is

What volume of oxygen gas $(O_2)$ measured at $0^\circ C$ and 1 atm, is needed to bum completely 1L of propane gas $(C_3H_8)$ measured under the same conditions?

Green chemistry means such reactions which

The dissociation equilibrium of a gas $ AB_2 $ can be represented as $2 A B_2(g) \rightleftharpoons 2 A B (g) + B_2 (g) $ The degree of dissociation is $x$ and is small compared to $1$. The expression relating the degree of dissociation (x) with equilibrium constant $K_p$ and total pressure $p$ is

Which of the following are not state functions? (I) q + W (II) q (III) w (IV) H-TS

Standard free energies of formation (in kj/mol) at 298 K are -237.2, -394.4 and -8.2 for $H_2O(l),CO_2(g) $ and pentane (g), respectively. The value of $E^0_{cell} $ for the pentane-oxygen fuel cell is

If uncertainty in position and momentum are equal, then uncertainty in velocity is

Equal volumes of three acid solutions of pH 3, 4 and 5 are mixed in a vessel. What will be the $ H^+ $ ion concentration in the mixture?