basics

Question 1

what is meant by weighted mean mass

Answer 1

(The mean/average mass) taking into account the
relative abundancies of the isotopes

Question 2

reasons for using catalysts in terms of benefits to environment

Answer 2

(Reaction can be carried out at) lower temperatures /
lower energy demand
Less (fossil) fuels burnt / less CO2 emissions

Question 3

halogens in aqueous and organic solution

Answer 3

Cl-Br-I
aqueous: green, orange, brown
organic: green ,orange, purple

Question 4

use of infrared spectroscopy

Answer 4

-to monitor gases causing air pollution (e.g. CO and NO from car
emissions)
-in modern breathalysers to
measure ethanol in the breath

Question 5

control of blood pH

Answer 5

by carbonic acid (H2CO3) buffer solution in plasma

Question 6

define transition metals

Answer 6

metals that form ions with incomplete d subshells