Group 7 Flashcards
(15 cards)
What is the trend in Boiling point down group 7
Increases
Stronger Van de waals forces as atom increases in size
What is the trend in electronegative down group 7
Why
Decreases
Atomic radius increases so the attraction is lower
What do you use to test for halide ions
Acidified AgNO3
Result and reaction for Cl- test
White precipitation
Ag+ + Cl- —> AgCl (s)
What is the result and equation for the test of Br-
Cream precipitation
Ag+ + Br- —> AgBr (s)
What is the result and equation for the test for I-
Yellow precipitation
Ag+ + I- —> AgI (s)
What is the trend in oxidising ability down group 7
Why
Decreases
Atom size increases so can’t attract electrons easily
What is the trend of reducing agent of halide down the group
Why
Increases
Halide atom larger so can give off electron easier
What are the potential risks of adding chlorine to drinking water
It is toxic and damages respiratory system
What is the type of reaction between chlorine and water
Why
Disproportionation
Chlorine is both oxidised and reduced
What is the equation to make bleach
Cl2 + 2NaOh —> NaCl + NaCIO + H20
NaCIO
What is desaltination
Converters saltwater into clean potable water
Advantages of desalination
Safe drinking water
Disadvantages of desalination
Uses lots of energy
