General Science

Which of the following is most closely associated with mixture?

A combination of substances retaining their chemical identities
B solid-to-gas change without passing through liquid
C polyvinyl chloride polymer
D corrosion product formed mainly on iron/steel

In general science, neutron refers to:

A amount of solute relative to a specified quantity
B solid-to-gas change without passing through liquid
C uncharged subatomic particle
D calcium sulfate hemihydrate

Which statement correctly identifies common salt?

A substance changing colour over a characteristic pH range
B arrangement of elements by atomic number and recurring properties
C elements generally lacking typical metallic properties
D sodium chloride

Which of the following is most closely associated with glass?

A negatively charged subatomic particle
B anything having mass and occupying space
C chemical oxygen demand, oxygen equivalent needed for chemical oxidation of substances in water
D amorphous inorganic solid commonly based on silica

What is the best description of BOD?

A biochemical oxygen demand, oxygen consumed by microbes decomposing organic matter in water
B aqueous solution containing acetic acid
C O3, allotrope of oxygen
D sodium carbonate decahydrate

In general science, washing soda refers to:

A smallest unit of an element retaining its chemical identity
B substance used to control pests
C sodium carbonate decahydrate
D atoms of the same element with different neutron numbers

Which statement correctly identifies PTFE/Teflon?

A fluoropolymer known for chemical resistance and low friction
B sodium chloride
C sodium hydrogen carbonate, NaHCO3
D substance dissolved in a solution

In general science, activation energy refers to:

A pure substance formed by chemical combination of elements in fixed proportions
B arrangement of elements by atomic number and recurring properties
C number of protons in the nucleus
D energy barrier associated with a reaction pathway

Which statement correctly identifies compound?

A elements generally showing conductivity, malleability and ductility
B ionic compound of cations and anions
C energy barrier associated with a reaction pathway
D pure substance formed by chemical combination of elements in fixed proportions

In general science, filtration refers to:

A separation of insoluble solids from a fluid using a filter
B large molecule made of repeating structural units
C loss of electrons or increase in oxidation state
D rapid reaction with an oxidant commonly releasing heat

Which of the following is most closely associated with mole?

A gain of electrons or decrease in oxidation state
B SI amount-of-substance unit containing Avogadro’s number of entities
C substance releasing usable energy in combustion or another process
D small molecule that can form a polymer

In general science, NPK fertiliser refers to:

A calcium hypochlorite-based bleaching/disinfecting material
B separation of insoluble solids from a fluid using a filter
C homogeneous mixture of solute and solvent
D fertiliser supplying nitrogen, phosphorus and potassium

What is the best description of carbon monoxide?

A CO, toxic product of incomplete combustion
B sodium hydrogen carbonate, NaHCO3
C substance producing ions in solution or molten state
D substance dissolved in a solution

In general science, polyethylene refers to:

A amount of solute relative to a specified quantity
B calcium sulfate hemihydrate
C polymer produced from ethene
D solid-to-gas change without passing through liquid

Which of the following is most closely associated with vinegar?

A synthetic polyamide polymer
B fossil fuel consisting mainly of methane
C chemical/electrochemical deterioration of a material
D aqueous solution containing acetic acid

What is the best description of element?

A Group 1 metals other than hydrogen
B pure substance whose atoms have the same atomic number
C positively charged subatomic particle
D positively charged ion

Which of the following is most closely associated with rust prevention?

A positively charged ion
B methods such as painting, galvanising or alloying that reduce corrosion
C measure related to hydrogen-ion activity/concentration
D Group 1 metals other than hydrogen

What is the best description of common salt?

A atom or group of atoms carrying net electric charge
B Group 18 elements with very low reactivity
C sodium chloride
D two or more atoms chemically bonded

Which of the following is most closely associated with salt?

A ionic compound of cations and anions
B NH3, basic nitrogen compound used in fertilisers
C acidic precipitation associated mainly with sulfur and nitrogen oxides
D calcium oxide

Which statement correctly identifies electrolyte?

A substance donating H+ in Brønsted-Lowry theory
B substance producing ions in solution or molten state
C horizontal row in the periodic table
D atoms of the same element with different neutron numbers

In general science, atomic number refers to:

A aqueous solution containing acetic acid
B number of protons in the nucleus
C component that dissolves the solute
D sodium carbonate decahydrate

In general science, PTFE/Teflon refers to:

A fluoropolymer known for chemical resistance and low friction
B calcium sulfate dihydrate
C CH4, simplest alkane and major natural-gas component
D CO, toxic product of incomplete combustion

In general science, gypsum refers to:

A calcium sulfate dihydrate
B substance accepting H+ or producing OH− in water
C atom or group of atoms carrying net electric charge
D Group 18 elements with very low reactivity

What is the best description of filtration?

A vertical column in the periodic table
B number of protons plus neutrons
C elements showing intermediate metal/non-metal properties
D separation of insoluble solids from a fluid using a filter

Which of the following is most closely associated with distillation?

A separation based mainly on differences in boiling points
B compressed natural gas, mainly methane
C reaction absorbing heat
D amorphous inorganic solid commonly based on silica