Class 11th

Ca plays important role in Neuromuscular function and interneuronal transmission. The daily requirement of Mg and Ca in the human body is estimated to be 200 – 300mg. All enzymes that utilise ATP in phosphate transfer require Mg as the cofactor. The bone in human body is NOT an inert and unchanging substance.

A, B and C are correct statements. The H-H bond dissociation enthalpy is the highest for a single bond between two atoms of any element. Hydrogen does not reduce oxides of metals that are more active than iron.

PV = nRT
P = nRT . (1/V)
Plot of P vs (1/V) would be straight line passing through origin having slope = nRT.
At high temperatures, P vs (1/V) would have greater slope.

Covalent bonding is NOT an intermolecular force while rest all are considered as intermolecular forces.

σ1s < 1s < 2s < 2s < (2px = 2py) < 2pz < (2px = π2py) < *2pz is the correct order of energy of MO for homo nuclear diatomic species N?

AlCl? , BeCl? and PCl? does not obey octet rule.
AlCl? and BeCl? both are electron-deficient species having six electrons in valence shell of central atom whereas PCl? has ten electrons in valence shell of phosphorous.
The structures are :

Among isoelectronic monoatomic species, size is inversely proportional to atomic number. Hence among isoelectronic species Na? , O²? , N³? , F? (having the nearest noble gas configuration);
Order of size is Na? < F? < O? < N?
N³? has least atomic number hence the largest size

nm = 2l + 1
As there are (2l + 1) number of permissible values of magnetic quantum number.
Hence, l = (nm - 1)/2

An Atom has three fundamental particles-electron, proton and neutron. The mass of the electron is 9.10939 * 10? ³¹ kg. Neutrons and protons, both are collectively known as nucleons. All the isotopes of a given element show same chemical properties. Dalton's atomic theory, regarded atom as an ultimate particle of matter.

20 g of 20% CaCO? = 20 * (20/100) = 4 g CaCO?
CaCO? (100 g) - (1200 K)-> CaO + CO? (44 g)
According to the reaction,
100 g of CaCO? → 44 g of CO?
4 g CaCO? → (4*44)/100 g of CO?
= 1.76 g of CO?