Chemistry Concepts for Year 12

What is the mole ratio in the reaction 2H2 + O2 -> 2H2O?

• 2:2:1

• 1:2:2

• 1:1:1

• 2:1:2

Define stoichiometry and its importance in chemical reactions.

• Stoichiometry deals exclusively with the physical properties of substances.

• Stoichiometry is a method for measuring temperature changes in reactions.

• Stoichiometry is only relevant in biological processes.

• Stoichiometry is essential for quantifying relationships in chemical reactions, ensuring accurate measurements and predictions of reactants and products.

Calculate the mass of NaCl produced from 0.5 moles of Na and excess Cl2.

• 22.99 g

• 29.22 g

• 58.44 g

• 35.45 g

What are the physical properties of metals?

• The physical properties of metals include conductivity, malleability, ductility, luster, high density, and high melting and boiling points.

• Absence of luster and low melting points

• Poor conductivity and high reactivity

• Brittleness and low density

Explain the term 'ductility' in relation to metals.

• Ductility describes the hardness of a metal when subjected to heat.

• Ductility is the ability of a metal to be stretched into a wire or deformed without breaking.

• Ductility is the ability of a metal to conduct electricity efficiently.

• Ductility refers to a metal's resistance to corrosion.

What is the electron configuration of a typical metal?

• [noble gas] ns^2 (for alkaline earth metals) or [noble gas] ns^2 nd^1-10 (for transition metals)

• [noble gas] ns^2 np^1

• [noble gas] ns^2 nd^11

• [noble gas] ns^1

Describe the structure of alkanes and provide an example.

• An example of an alkane is ethylene (C2H4).

• An example of an alkane is butane (C4H10).

• Alkanes are characterized by double bonds between carbon atoms.

• An example of an alkane is propane (C3H8).

What is the general formula for alkenes?

• CnH2n

• C2nHn

• CnH2n+1

• CnH2n-2

Identify the functional group present in alcohols.

• Carboxyl group (-COOH)

• Carbonyl group (C=O)

• Amino group (-NH2)

• Hydroxyl group (-OH)

What is the difference between saturated and unsaturated hydrocarbons?

• Saturated hydrocarbons are liquid at room temperature; unsaturated hydrocarbons are solid at room temperature.

• Saturated hydrocarbons contain only double bonds; unsaturated hydrocarbons contain only single bonds.

• Saturated hydrocarbons have a higher molecular weight than unsaturated hydrocarbons.

• Saturated hydrocarbons have only single bonds; unsaturated hydrocarbons have double or triple bonds.