solubility

Question 1

aqueous solution

Answer 1

when water is used to dissolve a solid, liquid or gaseous substance

Question 1

solute

Answer 1

a chemical that is dissolved in a solution

Question 2

solvent

Answer 2

the substance in which the solute dissolves in, often a liquid

Question 3

how come polar molecules dissolve in water

Answer 3

because they are able to form hydrogen bonds with water molecules or the molecules can ionise in the water

Question 4

for a solution to be aqueous

Answer 4

the solvent must be water

Question 5

homogenous solution

Answer 5

the solute and solvent cannot be distinguished from each other visually, every part of the solution looks the same as every other part

Question 6

characteristics of solutions

Answer 6

homogenous, dissolved particles are too small to see, the amount of dissolved solute can vary from one solution to another

Question 7

what is the process of dissolving also called

Answer 7

dissolution

Question 8

following processes occur in dissolution

Answer 8

solute particles are attracted to some of the solvent particles, the particles of the solute are seperated from one another, some of the solvent particles are seperated to allow the solute particles to disperse throughout the liquid

Question 9

what are the different forces of attraction that need to be considered when a substance is determined to dissolve in water

Answer 9

the forces holding the particles of the substance/solute together before its added to the solvent, the forces holding the solvent molecules together, the forces that can form between the solute particles and solvent molecules

Question 10

what forces are between water molecules

Answer 10

hydrogen bonds and dispersion forces

Question 11

for a substance to dissolve…

Answer 11

the attractive forces between the solute and solvent particles must be similar to oor greater thaan the forces between the particcles in the solute and the forces between the solvent molecules

Question 12

how come wax and other non-polar substances not dissolve well in water

Answer 12

only intermolecular forces between these substances are dispersion forces whereas hydrogen bonds exist between water molecules, they are much stronger than the forces of attraction that could occur between water molecules and these substances , so the forces of attraction between the water molecules cannot be overcome

Question 13

when tthe two substances in the dissolving process are liquids they are

Answer 13

misicble

Question 14

when the two liquids do not dissolve each other they are

Answer 14

immiscible

Question 15

three ways that compoudds dissolve in water

Answer 15

1. by forming hydrogen bonds, 2. ionisation (formation of ions) 3. ionic compounds dissolve by ddissociation

Question 16

ethanol structure

Answer 16

C2H5OH, liquid at room temp, its molecules contain the polar OH group with lone pairs of electrons on the oxygen atom

Question 17

how can ethanol dissolve in water

Answer 17

the hydrogen bonded to the oxygen allows the foormation of hydrogen bonds, the strength of the solute-solute intermolecular forces are similar to the solute-solvent intermolecular forces

Question 18

polar molecule dissolving in water

Answer 18

the equation for dissolution place h20(l) above the arrow as no chemical change occurs

Question 19

what makes a polar moolecule less and more dissolving

Answer 19

the more polar the molecule, the more likely it will dissolve in water, the larger the non-polar section of the molecule the less likely it will dissolve

Question 20

when does ionisation in water occur

Answer 20

when the solute compound has one or more covalent bonds that are so polar they break when the compound is placed in water

Question 21

HCl + water forms

Answer 21

cl- ions and h3o+ ions

Question 22

HCL is said to ionise in water because

Answer 22

the Hcl molecule has broken apart to produce ions

Question 23

H3O+ bondiing

Answer 23

beconmes hydrated, three of the oxygens of h2O bonds to the hydrogens of H3O, one oxygen of H2O bonds to the hydrogen of H3)

Question 24

Cl- bonding when hcl dissolves

Answer 24

surrounded by six hydrogens from h2o bonded to the cl, described as hydrated

Question 25

is water included in the hcl and water reaction

Answer 25

yes as a reactant because there has been a chemical reaction/rearrangment of atoms to form new substances

Question 26

when does dissociation occur

Answer 26

when there are soluble ionic compounds

Question 27

what occurs when sodium chloride/ionic compound is added to water

Answer 27

the positive eds of the water molecules (hydrogens) are attracted to the negatively charged chloride ions, the negative end of the water molecules (oxygen) is attracted to the positive sodium ions

Question 28

what attraction oxxurs between an ion and polar molecule such as water

Answer 28

ion-dipole attarction

Question 29

what is ionisation, refering to sodium chloride

Answer 29

water molecules are in a constant stae of random motion, if the ion-dipole attarction is strong enough, the water molecules can pull the sodium and chloride ions on the outer part of the crystal out of the lattice and into the surronding solution