principles of chemistry

Question 1

anion

Answer 1

negatively charged ion

Question 2

cation

Answer 2

positively charged ion

Question 3

carbon nanotubes

Answer 3

each carbon

Question 4

diamond

Answer 4

each carbon is joined to four other carbons covalently. high melting point and does not conduct electricity

Question 5

graphite

Answer 5

bonded covalently to 3 other carbons, forming hexagonal ring layers.
this means there is one delocalised electron making it able to conduct electricity.
they can slide over each other due to no covalent bonds between the layers with weak intermolecular forces. so graphite is soft and slippery

Question 6

graphene

Answer 6

single layer of graphite
has properties making it useful in electronics and composites

Question 7

fullrenes

Question 8

covalent bonding

Answer 8

occurs between non metals where atoms share a pair of electrons. these bonds between atoms are strong

Question 9

mols formula

Answer 9

mass (g) = relative formula mass (g-1) x mol (mol)

Question 10

relative atomic mass

Answer 10

sum of the relative atomic masses of all the elements in the compound

Question 11

percentage yield

Answer 11

amount of product produced/max amount of products possible x 100

Question 12

when given the mass + elements, how do you create a balanced symbol equation

Answer 12

divide each substance by the relative formula mass (Mr)

divide the number of each mol by the smallest mol in the equation

if numbers arent whole, multiply them all by the same number to make it so. other than that, write an equation!! :D

Question 13

limiting reactant

Answer 13

the reactant that is used up

Question 14

percentage mass formula

Answer 14

relative atomic mass (Ar) x number of atoms/relative formula mass of compound (Mr)
x 100

Question 15

seperation

Answer 15

simple distillation
fractional distillation
filtration
crystallisation
chromatography

Question 16

rf value

Answer 16

distance moved by substance/distance moved by solvent

Question 17

stationary phase

Answer 17

the phase that remains stationary

Question 18

mobile phase

Answer 18

the phase that moves through the stationary phase

Question 19

concentration formula

Answer 19

mols/volume

Question 20

1dm^3 -> 1cm^3

Answer 20

x1000

Question 21

how do you work out the limiting reactant

Answer 21

convert the mass into mols for both reactants

compare the ratio between the mols calculated and the one provided in the chemical equation. find out which one is the limiting reactant

use said ratio to find the mols of the product produced, then calculate the mass

Question 22

what factors effect the actual yield

Answer 22

some products are lost when removed from the reaction mixture
unwanted reactions
reversible