Among the elements Ca, Mg, P and Cl, the order of increasing atomic radii is
Mg< Ca< Cl< P
Cl <P <Mg< Ca
P <Cl< Ca< Mg
Ca <Mg <P < Cl
B.
Cl <P <Mg< Ca
With increase in the number of electrons in the same shell, the atomic radii decreases due to increase in effective nuclear charge. However, atomic radii increases, as the number of shells increases. Thus, on moving down a group atomic radii increases. The electronic configuration of the given element is
Mg12 = [Ne] 3s2
Ca20 = [Ar]4s2
P15 = [Ne] 3s2 3p2
Cl17 = [Ne]3s2 3p5
In Mg, P and Cl, the number of electrons are increasing in the same shell, thus the order of their atomic radii is
Cl <P < Mg
In Ca, the electron is entering in higher shell, thus, it has the highest atomic radii among the given. Thus, the order of radii is
Cl<P <Mg< Ca
The reaction
2A(g) + B(g) 3C(g) + D(g)
is begun with the concentrations of A and B both at an initial value of 1.00 M. When equilibrium is reached, the concentration of D is measured and found to be 0.25 M. The value for the equilibrium constant for this reaction is given by the expression
[(0.75)3 (0.25)] [(1.00)2 (1.00)]
[(0.75)3 (0.25)] [(0.50)2 (0.75)]
[(0.75)3 (0.25)] [(0.50)2 (0.25)]
[(0.75)3 (0.25)] [(0.75)2 (0.25)]
The pressure exerted by 6.0g of methane gas in a 0.03 m3 vessel at 129°C is (Atomic masses: C = 12.01, H = 1.01 and R= 8.314JK-1 mol-1)
215216 Pa
13409 Pa
41648 Pa
31684 Pa
Match List I (Equations) with List II (Types of process) and select the correct option.
List I (Equation) |
List II (Types of process) |
||
A. | 1. | Non-spontaneous | |
B. | 2. | Equilibrium | |
C. | 3. | Spontaneous and endothermic | |
D. | T > | 4. | Spontaneous |
A | B | C | D |
1 | 2 | 3 | 4 |
A | B | C | D |
3 | 4 | 2 | 1 |
A | B | C | D |
4 | 1 | 2 | 3 |
A | B | C | D |
2 | 1 | 1 | 3 |
Some of the properties of the two species, are described below. Which one of them is correct?
Dissimilar in hybridisation for the central atom with different structures
Isostructural with same hybridisation for the central atom
Isostructural with different hybridisation for the central atom
Similar in hybridisation for the central atom with different structures
What is the value of electron gain enthalpy of Na if IE1 of Na = 5.1 eV?
-5.1 eV
-10.2 eV
+2.55 eV
+10.2eV