Chemistry — 1999

Which of the following atoms contains the highest number of electrons in the outermost shell?

What is the electronic configuration of an element represented as 19 9 X?

Pauli Exclusion Principle is related to

Which of the orbitals 4s, 4p, 4d and 4f has the lowest energy?

Two radioactive elements Q and S have half-life periods of 10 hours and 20 hours respectively. Therefore

Calcium atom ionizes by

Which of the following properties increases down a group in the Periodic Table?

In the Periodic Table, the elements that loss electrons most readily belong to

Which of the following reactions is not feasible?

Which of the following halogens is the most reactive?

The crystal layers in graphite are held together by

Which of the following compounds has the highest ionic character?

If an element with high electron affinity combines with another element with low ionization energy the bond formed will be mainly

One mole of a compound M(HCO 3 ) 2 has a mass of 162g. Calculate the relative atomic mass of M. [H = 1, C =12, O = 16]

Exhaust fumes discharged from a smoky vehicle gradually become invisible as a result of

Which of the following movements can be described as random motion?

Equal volumes of CO 2 cnd CO at s.t.p have the same

Gas molecules are said to be perfectly elastic because

What volume of hydrogen is produced at s.t.p. When 2.60 g of zinc reacts with excess HCI according to the following equation? Zn (s) + 2HCI (aq) → ZnCI 2(aq) + H 2(g) [Zn = 65; 1 mole of a gas occupies 22.4dm 3 at s.t.p]

Helium is preferred to hydrogen in filling balloons because hydrogen

30cm3 pf hydrogen at s.t.p combine with 20cm3 of oxygen to form steam according to the following equation 2H2(g) + O2(g) → 2H2O(g). Calculate the total volume of the gaseous mixture at the end of the reaction

An exothermic reaction is one which involves

Which of the following is an acid salt?

Which of the following compounds dissolves in water to form a solution with pH below 7?

If the solubility of KHCO 3 is 0.40 mole dm -3 at room temperature , calculate the mass of KHCO 3 in 100dm 3 of the solution at this temperature. [KHCO 3 = 100hmol ]

The property of calcium chloride which makes it useful as a drying agent is that it is

Which of the following lowers the activation energy of a chemical reaction?

Consider the reaction represented by the following equation: H 2(g) + 1 2(g) → 2HI (g) . The number of effective collisions of molecules of the reactants decreases as

What will be the effect of increase in pressure on the following system at equilibrium? 2NH 2(g) N 2(g) + 3H 2(g)

Which of the following is not correct about oxidation number convention? The oxidation number of a/an

Equal volumes of water were added to one mole of each of the following compounds. Which of them produced the largest number of ions

When dilute copper (ll) chloride solution is electrolysed, the reaction at the cathode is represented by the equation

How many carbon atoms are present in one molecule of 2-methylpropane?

Which of the following is the most reactive towards bromine?

Which of the following compounds is unsaturated?

Which of the following compounds reacts with sodium hydroxide to form a salt?

Alkanoates are produced from alkanols by

Which of the following is a secondary alkanol?

Geometric (cis-trans) isomerism is exhibited by

Which of the following is needed to produce slag during the extraction of iron in the blast furnace?

Environmental pollution problems are generally more severe in countries which have

The greenhouse effect is a climatic condition associated with the presence of excess