Potassium Chloride solid does not conduct electricity because

• Potassium Chloride solid does not conduct electricity because A. it is a covalent compound
• B. strong cohesive forces make its ions immobile
• C. strong cohesive force makes its molecule immobile
• D. each of potassium and chlorine structures contain noble gas structure

In which of the following is the entropy change positive?

• A) Thermal dissociation of ammonium chloride
• B) Reaction between an acid and a base
• C) Addition of concentrated acid to water
• D) Dissolution of sodium metal in water

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

• A. element in the free state is zero
• B. monatomic ion is equal to its charge
• C. alkali meta like sodium in its compounds is + 1
• D. atom of a diatomic molecules is + 2

The collision between ideal gas molecules are considered to be perfectly elastic because

• A. they collide without losing energy
• B. they move randomly in a straight line
• C. their average kinetic energy is variable
• D. the distance between them is large compared to their size

Which of the following ions require the largest quantity of electricity for discharge at an electrode?

• A. 4.0 moles of Cl^-
• B. 3.0 moles of Na⁺
• C. 2.5 moles of Cu²⁺
• D. 2.0 moles of Al³⁺

In an electrochemical cell, polarization is caused by

• A) Oxygen
• B) Hydrogen
• C) Tetraoxosulphate(IV) acid
• D) Chlorine

Which of the following statement is correct about the periodic table?

• A. Elements in the same period have the same number of valency electron
• B. The valence electron of the elements in the same period increase progressively across the period
• C. Elements in the same group have the same number of electron shells
• D. The non-metallic properties of the elements tend to decrease across each period

In the extraction of iron in the blast furnace, limestone is used to

• A) release CO₂ ?for the reaction
• B) reduce the iron ore
• C) increase the strength of the iron
• D) remove impurities

3.0g of a mixture of potassium carbonate and potassium chloride were dissolved in a 250cm³ standard flask. 25cm³ of this solution required 40.00cm³ of 0.01M HCl for neutralization. What is the percentage by weight of k₂CO₃ in the mixture? (k = 39, 0 = 16, C = 12)

• A) 92
• B) 89
• C) 72
• D) 826

An organic functional group which can likely decolorize ammoniacal silver nitrate is?

• A. alkene
• B. alkane
• C. alkyne
• D. alkanol