group-7 and ion tests Flashcards
what is the trend of boiling points down group 7
increases down the group
due to increasing strength of van der waals forces as the size and relative mass of the molecules increases
what is the trend of electronegativity down group 7
decreases
due to their outer shell electrons are further from the nucleus and thus are more shielded because they have more inner electrons
what is the equation for making bleach
2NaOH + Cl2——- NaClO + NaCl +H2O
what is the trend of reducing power of the halides
it increases down the group
as attraction between nucleus and outer shell electrons decreases so halogens can lose their outer shell electrons easier
what are the observations from the reaction of sodium bromide with sulfuric acid
steamy fumes
what are the observations from the reaction of sodium iodide with sulfuric acid
bad egg smell
black solid iodine
yellow solid sulfur
steamy fumes
what do you get if you react chlorine with water
a mixture of chlorate ions ,chloride ions and hydrogen ions
what are the products of the reaction of chlorine and sodium hydroxide
sodium chlorate NaClO
sodium chloride NaCl
water H2O
why is chlorine used in water treatment
as the benifits outweigh the risks
how do you test for group 2 metal ions
the flame test
what colour flame do calcium ions produce
brick red flame
what colour flame do stronium ions produce
red flame
what colour flame do barium ions produce
pale green flame
how do you test for ammonium ions
using a damp piece of red litmus paper
after adding dilute sodium hydroxide
and gentley heating
how do you test for sulfate ions
adding barium chloride solution if a white precipitate forms sulfate ions are present
as barium sulfate forms
