acids, alkalis and indicators

Question 1

what are the three aqueous solutions found in many household chemicals?

Answer 1

acids

alkaline

neutral

Question 2

why can acids and alkalis cause problems?

Answer 2

corrosive

toxic

harmful to the environment

Question 3

why are these particular soloution’s hazards indentified by international symbols?

Answer 3

indicated precautions that need to be taken when handling them

Question 4

what do you measure the acidity or alkalinity of a soloution on?

Answer 4

pH scale

Question 5

what do most soloutions lie between on the pH scale?

Answer 5

0 and 14

Question 6

what number is considered neutral?

Answer 6

7

Question 7

alkalis have a pH ———————– than 7 and acids have a pH ———————- than 7

Answer 7

greater

lower

Question 8

the ———- the pH the ————— acidic the soloution

Answer 8

lower

more

Question 9

how do you find the pH of a soloution?

Answer 9

indicators

Question 10

what are indicators?

Answer 10

substances that change colour depending on the pH

Question 11

what does a universal indicator do?

Answer 11

contains mixture of different indicators

produces a range of colours depending on pH

Question 12

litmus indicator turns ——— in alkaline solutions and ———— in acidic solutions

Answer 12

blue

red

Question 13

methyl orange indicator turns ——— in alkaline solutions and ———— in acidic solutions

Answer 13

yellow

red

Question 14

phenolphthalein indicator turns ——— in alkaline solutions and ———— in acidic solutions

Answer 14

pink

colourless

Question 15

what is an ion?

Answer 15

an atom that has become charged by losing or gaining electrons

Question 16

losing electrons forms ——– ions e.g ———-

Answer 16

positive

Na+ , H+

Question 17

gaining electrons forms ——– ions e.g ———-

Answer 17

negative

Cl- , Br- , S2-

Question 18

how are polyatomic ions formed? e.g?

Answer 18

when small groups of atoms, held together by covalent bonds, lose or gain electrons

OH- , NO3-

Question 19

what do acids produce when they dissolve in water?

Answer 19

excess of hydrogen ions (H+)

Question 20

what do alkalis produce in water?

Answer 20

hydroxide ions (OH-)

Question 21

the ——– the no. of H+ ions in a certain volume the ———— their —————

Answer 21

higher

higher

concentration

Question 22

the higher their ———- the more —— the solution and the——– the ——-

Answer 22

concentration

acidic

lower

pH

Question 23

the ——– the concentration of ———– the ——- alkaline the solution and the ——– the ——–

Answer 23

higher

hydroxide

more

higher

pH

Question 24

neutral solutions have a pH of —— and contain ——- ——— concentrations of ———- and —————

Answer 24

7

low

equal

hydrogen ions

hydroxide ions