chem topic 1

Question 1

what is chemistry

Answer 1

study of properties structures and composition of matter

Question 2

matter state can be interchanged from one to the other depending on

Answer 2

environmental temperature

Question 3

processes that take in heat

Answer 3

endothermic

Question 4

processes that take out heat

Answer 4

exothermic

Question 5

properties of solids

Answer 5

definite mass shape and volume
cannot be compressed
they do not flow

Question 6

properties of liquids

Answer 6

have definite mass volume
indefinite shape
not easily compressed
they easily flow

Question 7

properties of gases

Answer 7

definite mass
indefinite volume and shape
easily compressed
easily flow

Question 8

define pure substances

Answer 8

this is a substance made up of only one component eg distilled water

Question 9

define a mixture

Answer 9

a substance that is made up of two or more substances in which the components making up the mixture retain both their chemical and physical properties eg sand and water

Question 10

define a drug

Answer 10

a substance that is natural or manufactured that when taken in can alter the normal functions of the body

Question 11

define medicine

Answer 11

any drug that is taken to cure a specific disease

Question 12

state two types of medicines

Answer 12

over the counter drugs
prescribed drugs

Question 13

define over the counter drugs

Answer 13

drugs that can be accessed or bought without need of a prescription from a qualified doctor

Question 14

define prescribed drugs

Answer 14

this are drugs which are accessed and used by use of a prescription from a qualified doctor

Question 15

define prescription

Answer 15

this is a written instruction on the type of drug and how it should be used

Question 16

define dose/dosage

Answer 16

this is the amt of medicine that is prescribed by a medical doctor to be used for a period of time

Question 17

roles of chem to the society

Answer 17

manufacture of:
drugs to fight diseases
fertilizers for food production to fight hunger
cheap alternative fabrics such as nylon plastics for roofing packaging and domestic use
detergents

Question 18

importance of chem

Answer 18

it is a career subject
helps and assists in manufacture of products that ease our day to day life
impacts skills and knowledge in various areas
we learn about various chemicals and how they manufacture goods
provides intellectual fulfilment and an interest for further learning

Question 19

branches of chemistry

Answer 19

analytical chemistry
physical chemistry
organic chemistry
*inorganic chemistry

Question 20

reasons for using glass

Answer 20

its easier to clean
transparent hence one is able to make clear observation
does not react to chemicals or other reagents
withstands high temperatures when heating substancs

Question 21

chimney

Answer 21

is a metallic cylinder where laboratory gases mix with air ignited at the top producing a flame

Question 22

collar

Answer 22

a metallic ring having the same diameter as the chimney .it opens and closes the air hole regulating the amt of air entering the chimney

Question 23

base

Answer 23

it is a flat metallic part that provides a steady support for the bunsen burner

Question 24

jet

Answer 24

it is a tiny metallic part with a hole that allows lab gases to get into the chimney

Question 25

gas inlet

Answer 25

it is an external connector that allow gases from gas cylinders to get into the bunsen burner

Question 26

air hole

Answer 26

it is an opening at the end of the chimney that allows air to mix with the gases

Question 27

how to light a bunsen burner

Answer 27

connect the bunsen burner to the external source of the gas by using a rubber tubing
ensure the air hole is closed
strike a match stick and place it at the top of the chimney
open the gas tap and the gases ignite to produce a flame

Question 28

luminous flame

Answer 28

bright yellow in colour
has four zones
produces a lot of light
produces soot
it is less hot
it is large and wavy
burns quietly

Question 29

non luminous

Answer 29

pale blue in colour
has three zones
does not produce soot
produce less light hence less visible
it is hotter
it is small and steady
burns producing noise

Question 30

comparison

Answer 30

sooty-not sooty
very hot-fairly hot
it is long and wavy-short and steady
has four zones-has three zones
bright yellow in colour-pale blue in colour