SWS3022 Exam 2*3 Questions and
Answers 100% Pass
What are the important soil solution constituents of inorganic soils? - ✔✔can contain
carbon, but are not based on carbon; simple
- metals, chemical nutrients, acids
- all ionic
What are the important soil solution constituents of organic soils? - ✔✔compounds of
carbon; dominated by C, H, and O; complex
- covalently bonded
- can be natural or synthetic
How do ions differ from the elements in the periodic table? - ✔✔Elements in the
periodic table are electrically neutral. Ions are stable forms of elements that acquire an
electrical charge by gaining or losing electrons.
ions - ✔✔stable forms of elements that acquire an electrical charge by gaining or losing
electrons
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,cations - ✔✔elements that lose electrons; positively charged
anions - ✔✔elements that gain electrons; negatively charged
hydration sphere - ✔✔when ions are surrounded by a sphere of water molecules
because of the charge of the ions and the charge of each pole of the water molecules
ion hydration - ✔✔when an ionic solid dissolves in a polar solvent like water, water
surrounds the ion (hydration sphere) to form a hydrated ion
How can ion hydration impact the size of cations in a soil? - ✔✔each ion has a different
ability to attract water
smaller = larger hydration sphere = larger cation
1:1 and 2:1 aluminosilicate clay minerals are WHAT? - ✔✔colloidal (small, large specific
surface area, highly reactive)
What are the 3 fundamental features of soil mineral colloids? - ✔✔small, large specific
surface area, highly reactive
reactivity is derived from large surface area and electrical charge
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, Reactivity in soil mineral colloids is derived from what two factors? - ✔✔large surface
area and electrical charge
How is cation exchange capacity measured? - ✔✔Take a mineral / clay / whatever that
is saturated with a cation, then flush them out with a stronger cation. The displaced
cations will be collected in a beaker, and the number of cations, and that number is the
amount of negative charges (CEC)
What are the fundamental building blocks for aluminosilicate clays and the dominant
ions comprising them? - ✔✔Tetrahedral sheets (silicon and oxygen) and octahedral
sheets (aluminum, oxygen, and hydroxide).
tetrahedral sheet - ✔✔one of the fundamental building blocks of aluminosilicate clays;
silicon based, share oxygen to interlock
octahedral sheet - ✔✔one of the fundamental building blocks of aluminosilicate clays;
aluminum based, surrounded by six OH groups
1:1 mineral - ✔✔one tetrahedral sheet and one octahedral sheet
2:1 mineral - ✔✔one octahedral sheet and two tetrahedral sheets; octahedral sheet is
sandwiched between the two tetrahedral sheets
Know the difference between a 1:1 and a 2:1 mineral. - ✔✔1:1 (Tetrahedral : Octahedral)
Katelyn Whitman, All Rights Reserved © 2025 3
Answers 100% Pass
What are the important soil solution constituents of inorganic soils? - ✔✔can contain
carbon, but are not based on carbon; simple
- metals, chemical nutrients, acids
- all ionic
What are the important soil solution constituents of organic soils? - ✔✔compounds of
carbon; dominated by C, H, and O; complex
- covalently bonded
- can be natural or synthetic
How do ions differ from the elements in the periodic table? - ✔✔Elements in the
periodic table are electrically neutral. Ions are stable forms of elements that acquire an
electrical charge by gaining or losing electrons.
ions - ✔✔stable forms of elements that acquire an electrical charge by gaining or losing
electrons
Katelyn Whitman, All Rights Reserved © 2025 1
,cations - ✔✔elements that lose electrons; positively charged
anions - ✔✔elements that gain electrons; negatively charged
hydration sphere - ✔✔when ions are surrounded by a sphere of water molecules
because of the charge of the ions and the charge of each pole of the water molecules
ion hydration - ✔✔when an ionic solid dissolves in a polar solvent like water, water
surrounds the ion (hydration sphere) to form a hydrated ion
How can ion hydration impact the size of cations in a soil? - ✔✔each ion has a different
ability to attract water
smaller = larger hydration sphere = larger cation
1:1 and 2:1 aluminosilicate clay minerals are WHAT? - ✔✔colloidal (small, large specific
surface area, highly reactive)
What are the 3 fundamental features of soil mineral colloids? - ✔✔small, large specific
surface area, highly reactive
reactivity is derived from large surface area and electrical charge
Katelyn Whitman, All Rights Reserved © 2025 2
, Reactivity in soil mineral colloids is derived from what two factors? - ✔✔large surface
area and electrical charge
How is cation exchange capacity measured? - ✔✔Take a mineral / clay / whatever that
is saturated with a cation, then flush them out with a stronger cation. The displaced
cations will be collected in a beaker, and the number of cations, and that number is the
amount of negative charges (CEC)
What are the fundamental building blocks for aluminosilicate clays and the dominant
ions comprising them? - ✔✔Tetrahedral sheets (silicon and oxygen) and octahedral
sheets (aluminum, oxygen, and hydroxide).
tetrahedral sheet - ✔✔one of the fundamental building blocks of aluminosilicate clays;
silicon based, share oxygen to interlock
octahedral sheet - ✔✔one of the fundamental building blocks of aluminosilicate clays;
aluminum based, surrounded by six OH groups
1:1 mineral - ✔✔one tetrahedral sheet and one octahedral sheet
2:1 mineral - ✔✔one octahedral sheet and two tetrahedral sheets; octahedral sheet is
sandwiched between the two tetrahedral sheets
Know the difference between a 1:1 and a 2:1 mineral. - ✔✔1:1 (Tetrahedral : Octahedral)
Katelyn Whitman, All Rights Reserved © 2025 3
