atmosphere and acids

Question 1

methyl orange indicator colours

Answer 1

acidic :red
neutral: yellow
alkaline :yellow

Question 2

phenolphthalein indicator colours

Answer 2

acidic : colourless
neutral: colourless
alkaline : pink

Question 3

red litmus paper colours

Answer 3

acidic : red
neutral: stays red
alkaline blue

Question 4

blue litmus paper colours

Answer 4

acidic : red
neutral: stays blue
alkaline blue

Question 5

composition of air

Answer 5

nitrogen 78%
oxygen 21%
carbon dioxide 0.04%
argon 0.96%

Question 6

what is element combustion

Answer 6

when an element reacts with oxygen to produce an oxide

Question 7

what is the equation for element combustion

Answer 7

element + oxygen -> element oxide

Question 8

how to dissolve an oxide

Answer 8

if they dissolve in water ,oxides tend to form an acidic or alkaline solution
- this depends on if the original element was a metal or non metal

Question 9

when metal oxides dissolve what do they form

Answer 9

alkaline solutions

Question 10

when non metal oxides dissolve what do they form

Answer 10

acidic solutions

Question 11

definition of an acid

Answer 11

h+ donor

Question 12

definition of a base

Answer 12

H+ accepter

Question 13

definition of an alkali

Answer 13

OH- donor

Question 14

what is the equation of an acid + base reaction

Answer 14

acid + base -> salt + water

Question 15

observation of an acid + base reaction

Answer 15

base disappears because its used up in the reaction

Question 16

equation of an acid + carbonate reaction

Answer 16

acid + carbonate -> salt + water + carbon dioxide

Question 17

observations of an acid + carbonate reaction

Answer 17

the carbonate disappears: because its used up in the reaction
there is effervescence: because co2 is produced