Period Table & Energy Random Retrieval

For which of these equilibria does a change in pressure have no effect on the yield of substances on the right-hand side of the equation?

(i) CH_4(g) + H₂O_(g) <=> 3H_2(g) + CO_(g)

(ii) 2HI_(g) <=> H_2(g) + I_2(g)

(iii) 2SO_2(g) + O_2(g) <=> 2SO_3(g)

(iv) H₂O_(g) + CO_(g) <=> H_2(g) + CO_2(g)

When iron(II) chloride solution mixes with silver nitrate solution some silver metal precipitates and the mixture reaches an equilibrium state.

Fe²⁺_(aq) + Ag⁺_(aq) <=> Fe³⁺_(aq) + Ag_(s)

When the aqueous layer is decanted off, the precipitate of silver redissolves on adding a solution of:

Using mean bond dissociation enthalpies, estimate the enthalpy of combustion Δ_cH of liquid ethanol

C₂H₅OH_(l) + 3O_2(g) => 2CO_2(g) + 3H₂O_(l)

The total O.N. of all the halogen atoms in these compounds ClO^-, BrO^-, ICl, XeF₄ is:

The carbonates of group 2 metals (M):

(i) have the formula of the form MCO₃

(ii) are insoluble in water

(iii) become more difficult to decompose on heating down the group

(iv) decompose on heating to the metal and carbon dioxide

A white crystalline solid gives a pale green colour in a flame. Adding silver nitrate to an acidified solution of the solid produces a white precipitate. The solid is:

What is the electron configuration of a magnesium atom?

What is the oxidation number of SULFUR in

SO₄^2-

What is the oxidation number of OSMIUM in

OsO₄

Which of these true statements help to explain why the values of the first ionisation enthalpies (energies) of the group 1 metals fall down the group from lithium to caesium?

(i) Down the group, the outer electron gets further from the nucleus

(ii) The charge on the nucleus increases down the group

(iii) Greater shielding means that the attraction between the nucleus and the outer electron reduces down the group

(iv) In all the atoms the outer electron is an s-electron