JK-TK/Newdata huggingface dataset:
Insects exhibit two types of reproducti processes. In some insects, the ova in t female are fertilised by the spermatozoa frc the male. This is a typical example of sexi reproduction, common in butterflies ai moths. In other insects like the black and t green aphids, the eggs are usually product without being fertilised and are able to --- into adult insects. This type of asexual reproduction is referred to ; parthenogenesis. Growth and Development in Insects
Majority of insects lay eggs that hatch int larvae, which is an immature stage, usual! quite different from the adults in morpholog and behaviour. Depending on the insec species a larva is referred to as a grub, maggot or a caterpillar. Generally the larv eats a lot, grows rapidly and sheds its cuticl several times until it reaches full size t< become a pupa. The pupa is an inactive, non feeding stage during which extensivi breakdown and re-organisation of body tissui occur, eventually giving rise to the imago o adult form. Such changes, callec metamorphosis, do occur in butterflies moths, bees, wasps and flies. Insects which pass through these stages, namely, egg-larva-pupa, into imago/adult in their developmenl are said to undergo complete metamorphosis. Development in a Housefly(An example of complete metamorphosis)
When the egg of a housefly is laid, it measures about 1mm in length. The eggs are laid in batches of between 100 to 150. The larvae which hatch from the eggs grow and feed on decaying matter. After several moults and increase in size, a Jarva reaches about 1cm in length. This takes about 5 days. After this, the larva changes into a pupa encased in a pupal case called die puparium, from which the adult fly later emerges. After emergence, the adult tgkes about two weeks of feeding and growing to attain sexual maturity, i.e. the males can mate and the females are able to lay eggs. Figure 4.14 summarises the life cycle of a housefly. Incomplete Metamorphosis
Development in some insects like the locust and cockroaches, involves the.egg hatching into a nymph which e!cie!y resembles the adult in every form, except for size and lack of sexual maturity.
the males can mate and the females are able to lay eggs.

Figure 4.14 summarises the life cycle of a housefly.

Incomplete Metamorphosis
Development in some insects like the locust and cockroaches, involves the.egg hatching into a nymph which e!cie!y resembles the adult in every form, except for size and lack of sexual maturity.

Pupa case Adult pushes out against the case
For such insects to reach the adult, stages, they undergo a series of moults.

before fully acquiring the adult size and attaining the sexual maturity.

These insects are said to undergo incomplete metamorphosis.

Development in a Cockroach(An example of incomplete metamorphosis)
Cockroaches produce eggs enclosed in a case in groups of between 10 - 15.

The case known as ootheca is made up of cfaitm.

The ootheca is usually deposited in moist dark and warm places, for example in cracks of furniture or crevices in walls.

It takes about a month before the small wingless nymphs emerge.

The nymphs feed, and moult about ten times with the total nymphal period lasting about 16 days for all the adult structure to become fully developed.

Role of Hormones in InsectMetamorphosis
In insects metamorphosis is controlled by hormones.

The hormones are produced in three glands namely;
Neurosecretory cells in the brain ganglia, a pair of corpora allata (singular Corpus allatum) located in the mandibular segment and prothoracic glands in the thorax.

During larval stages of the insect the corpora ailata produces juvenile hormone,
This leads to formation of larval cuticle., therefore moulting does not go beyond the larval stage.

When the larva matures, the corpus allatum disintegrates-
At this time the neurosecretory cells stimulate the prothoracic glands to produce moulting hormone (ecdysone).

Ecdysone is responsible for moulting in insects leading to the laying of the adult cuticle.
Study the equation below. Hydrated copper (II) sulphate white Solid T + Colourless Liquid H a) Identify the; i).White solid T ............................................................... ii). C olourless liquid H .......................................................{1 m ark} b) If H ydrated C opper (II) Sulphate had FIVE w ater m olecules, w rite the chemical equation for the above reaction. {1 m ark} .......................................................................................................................... .......................................................................................................... 10. During the 2012 London O lympic G ames, samples from four D ecathlon participants (Morgan, Bolton, Jimmy and Jade) w ere taken and tested for presence of two illegal steroids A and B. Paper chromatography w as used for the test. Steroid A Steroid B Morgan Bolton Jimmy Jade a) Which athlete(s) tested positive for the illegal steroid? {1 m ark} ........................................................................................................................... ............................................................................... b) On the filter paper representation below, draw the results for the Bolton.{2 marks} 1 1 . T h e c u r v e s b e l o w r e p r e s e n t t h e v a r i a t i o n o f t e m p e r a t u r e w i t h t i m e w h e n
pure and impure samples of a solid w ere heated. Solid K Temperature in ˚C Solid F Time in seconds a) Which of the two curves shows the variation in temperature for pure solid? Explain.{2 m arks} b) If 300 grams m ore of the pure substance w as added to the sample, show on the graph the time that the sample the pure substance w ill boil. {½ m ark}
c) On the graph above, indicate the boiling point of the pure substance.{½ m ark} 12. Arnold, a student from Starehe Boys’ C entre Situated 3050m above the sea level boiled 100cm3 of pure w ater. Another student, Annette, from Mombasa 0 m etres above the sea level boiled the same volume of pure water. i. Which of the two students took the longest time to boil w ater? {1mark} .................................................................................................................. ii. Explain your answer in d, i) above? {1 m ark} ........................................................................................................................... ........................................... 13.
Introduction​ ​to​ ​chemistry 1. Wooden​ ​splints​ ​F​ ​and​ ​G​ ​were​ ​placed​ ​in​ ​different​ ​zones​ ​of​ ​a​ ​Bunsen​ ​burner​ ​flame. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​The​ ​diagram​ ​below​ ​ ​gives​ ​the​ ​observations​ ​that​ ​were​ ​made (a)​ ​Explain​ ​the​ ​difference​ ​between​ ​F​ ​and​ ​G (b)​ ​Name​ ​the​ ​type​ ​of​ ​flame​ ​that​ ​was​ ​used​ ​in​ ​the​ ​above​ ​experiment 2. The diagrams​ ​below​ ​represent​ ​a​ ​list​ ​of​ ​apparatus​ ​which​ ​are​ ​commonly​ ​used​ ​in​ ​a​ ​chemistry laboratory:- (a)​ ​Give​ ​the​ ​correct​ ​order​ ​of​ ​the​ ​apparatus,​ ​using​ ​the​ ​letters​ ​only​,​ ​to​ ​show​ ​the​ ​correct arrangement ​ ​ ​ ​ ​ ​ ​that​ ​can​ ​be​ ​used​ ​to​ ​prepare​ ​and​ ​investigate​ ​the​ ​nature​ ​of​ ​PH​ ​of​ ​a​ ​sample​ ​of​ ​onion solution (b)​ ​Name​ ​one​ ​chemical​ ​substance​ ​and​ ​apparatus​ ​that​ ​is​ ​needed​ ​in​ ​this​ ​experiment 3. (a)​ ​When​ ​the​ ​air-hole​ ​is​ ​fully​ ​opened,​ ​the​ ​bunsen​ ​burner​ ​produces​ ​a​ ​non-luminous​ ​flame. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​Explain (b)​ ​Draw​ ​a​ ​labelled​ ​diagram​ ​of​ ​anon-luminous​ ​flame 4. (a)​ ​What​ ​is​ ​a​ ​drug?
(a)​ ​When​ ​the​ ​air-hole​ ​is​ ​fully​ ​opened,​ ​the​ ​bunsen​ ​burner​ ​produces​ ​a​ ​non-luminous​ ​flame. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​Explain (b)​ ​Draw​ ​a​ ​labelled​ ​diagram​ ​of​ ​anon-luminous​ ​flame 4. (a)​ ​What​ ​is​ ​a​ ​drug? (b)​ ​Give​ ​two​ ​drugs​ ​that​ ​are​ ​commonly​ ​abused​ ​by​ ​the​ ​youth. 5. The​ ​diagram​ ​below​ ​shows​ ​three​ ​methods​ ​for​ ​collecting​ ​gases​ ​in​ ​the​ ​laboratory
(a)​ ​Name​ ​the​ ​methods​ ​A​ ​and​ ​B (b)​ ​From​ ​the​ ​methods​ ​above,​ ​identify​ ​one​ ​that​ ​is​ ​suitable​ ​for​ ​collecting​ ​sulphur​ ​(IV) oxide. ​ ​ ​ ​ ​Explain 6. A​ ​mixture​ ​of​ ​hexane​ ​and​ ​water​ ​was​ ​shaken​ ​and​ ​left​ ​to​ ​separate​ ​as​ ​shown​ ​in​ ​the​ ​diagram below: State​ ​the​ ​identity​ ​of; (i)​ ​P​ ​………………………………..……..​ ​ ​ ​ ​ ​(ii)​ ​W​ ​………………………………….…. 7. The​ ​diagrams​ ​below​ ​are​ ​some​ ​common​ ​laboratory​ ​apparatus.​ ​Name​ ​each​ ​apparatus​ ​and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​state​ ​its​ ​use Diagram Name Use
(½mk​ ​) (½mk) (½mk) (½mk) 8.
A​ ​mixture​ ​of​ ​hexane​ ​and​ ​water​ ​was​ ​shaken​ ​and​ ​left​ ​to​ ​separate​ ​as​ ​shown​ ​in​ ​the​ ​diagram below: State​ ​the​ ​identity​ ​of; (i)​ ​P​ ​………………………………..……..​ ​ ​ ​ ​ ​(ii)​ ​W​ ​………………………………….…. 7. The​ ​diagrams​ ​below​ ​are​ ​some​ ​common​ ​laboratory​ ​apparatus.​ ​Name​ ​each​ ​apparatus​ ​and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​state​ ​its​ ​use Diagram Name Use
(½mk​ ​) (½mk) (½mk) (½mk) 8. The diagram​ ​below shows​ ​some parts​ ​of​ ​a​ ​Bunsen burner Explain​ ​how​ ​the​ ​parts​ ​labelled​ ​T​ ​and​ ​U​ ​are​ ​suited​ ​to​ ​their​ ​functions
9. The​ ​diagram​ ​below​ ​shows​ ​the​ ​appearance​ ​of​ ​two​ ​pieces​ ​of​ ​paper​ ​placed​ ​in​ ​different​ ​parts of​ ​a non-luminous​ ​flame​ ​of​ ​a​ ​Bunsen​ ​burner​ ​and​ ​removed​ ​quickly​ ​before​ ​they​ ​caught​ ​fire. (a)​ ​What​ ​do​ ​the​ ​experiments​ ​show​ ​about​ ​the​ ​outer​ ​region​ ​of​ ​the​ ​flame? (b)​ ​From​ ​the​ ​above​ ​experiment,​ ​which​ ​part​ ​of​ ​the​ ​flame​ ​is​ ​better​ ​to​ ​use​ ​for​ ​heating?Give a​ ​reason 10.
The​ ​diagram​ ​below​ ​shows​ ​the​ ​appearance​ ​of​ ​two​ ​pieces​ ​of​ ​paper​ ​placed​ ​in​ ​different​ ​parts of​ ​a non-luminous​ ​flame​ ​of​ ​a​ ​Bunsen​ ​burner​ ​and​ ​removed​ ​quickly​ ​before​ ​they​ ​caught​ ​fire. (a)​ ​What​ ​do​ ​the​ ​experiments​ ​show​ ​about​ ​the​ ​outer​ ​region​ ​of​ ​the​ ​flame? (b)​ ​From​ ​the​ ​above​ ​experiment,​ ​which​ ​part​ ​of​ ​the​ ​flame​ ​is​ ​better​ ​to​ ​use​ ​for​ ​heating?Give a​ ​reason 10. A​ ​crystal​ ​of​ ​copper​ ​(II)​ ​sulphate​ ​was​ ​placed​ ​in​ ​a​ ​beaker​ ​of​ ​water.​ ​The​ ​beaker​ ​was​ ​left standing​ ​for ​ ​two​ ​days​ ​without​ ​shaking.​ ​State​ ​and​ ​explain​ ​the​ ​observations​ ​that​ ​were​ ​made. 11. Study​ ​the​ ​information​ ​in​ ​the​ ​table​ ​below​ ​and​ ​answer​ ​questions​ ​that​ ​follow.
A​ ​crystal​ ​of​ ​copper​ ​(II)​ ​sulphate​ ​was​ ​placed​ ​in​ ​a​ ​beaker​ ​of​ ​water.​ ​The​ ​beaker​ ​was​ ​left standing​ ​for ​ ​two​ ​days​ ​without​ ​shaking.​ ​State​ ​and​ ​explain​ ​the​ ​observations​ ​that​ ​were​ ​made. 11. Study​ ​the​ ​information​ ​in​ ​the​ ​table​ ​below​ ​and​ ​answer​ ​questions​ ​that​ ​follow. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​(Letters​ ​given​ ​are​ ​not​ ​real​ ​symbols) Ions Electron​ ​arrangement Ionic​ ​radius​ ​(nm) A​+ B​+ C​2+ 2.8 2.8.8 2.8 0.95 0.133 0.065 Explain​ ​why​ ​the​ ​ionic​ ​radius​ ​of​ ​:- (a)​ ​B​+​​ ​is​ ​greater​ ​than​ ​that​ ​of​ ​A​+ ​ ​ ​(b)​ ​C​2+​​ ​is​ ​smaller​ ​than​ ​the​ ​of​ ​A​+ ​ ​Simple​ ​classification​ ​of​ ​substances 1. The​ ​diagram​ ​below​ ​shows​ ​the​ ​heating​ ​curve​ ​of​ ​a​ ​pure​ ​substance.​ ​Study​ ​it​ ​and​ ​answer​ ​the ​ ​questions​ ​that​ ​follow:
(a)​ ​What​ ​physical​ ​changes​ ​are​ ​taking​ ​place​ ​at​ ​points​ ​X​ ​and​ ​Z​? (b)Explain​ ​what​ ​happens​ ​to​ ​the​ ​melting​ ​point​ ​of​ ​sodium​ ​chloride​ ​added​ ​to​ ​this​ ​substance 2.
​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​(Letters​ ​given​ ​are​ ​not​ ​real​ ​symbols) Ions Electron​ ​arrangement Ionic​ ​radius​ ​(nm) A​+ B​+ C​2+ 2.8 2.8.8 2.8 0.95 0.133 0.065 Explain​ ​why​ ​the​ ​ionic​ ​radius​ ​of​ ​:- (a)​ ​B​+​​ ​is​ ​greater​ ​than​ ​that​ ​of​ ​A​+ ​ ​ ​(b)​ ​C​2+​​ ​is​ ​smaller​ ​than​ ​the​ ​of​ ​A​+ ​ ​Simple​ ​classification​ ​of​ ​substances 1. The​ ​diagram​ ​below​ ​shows​ ​the​ ​heating​ ​curve​ ​of​ ​a​ ​pure​ ​substance.​ ​Study​ ​it​ ​and​ ​answer​ ​the ​ ​questions​ ​that​ ​follow:
(a)​ ​What​ ​physical​ ​changes​ ​are​ ​taking​ ​place​ ​at​ ​points​ ​X​ ​and​ ​Z​? (b)Explain​ ​what​ ​happens​ ​to​ ​the​ ​melting​ ​point​ ​of​ ​sodium​ ​chloride​ ​added​ ​to​ ​this​ ​substance 2. (a)​ ​State​ ​two​ ​differences​ ​between​ ​luminous​ ​flame​ ​and​ ​non-luminous​ ​flame (b)​ ​It​ ​is​ ​advisable​ ​to​ ​set​ ​a​ ​Bunsen​ ​burner​ ​to​ ​luminous​ ​flame​ ​prior​ ​to​ ​an​ ​experiment. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​Explain 3.
(b)Explain​ ​what​ ​happens​ ​to​ ​the​ ​melting​ ​point​ ​of​ ​sodium​ ​chloride​ ​added​ ​to​ ​this​ ​substance 2. (a)​ ​State​ ​two​ ​differences​ ​between​ ​luminous​ ​flame​ ​and​ ​non-luminous​ ​flame (b)​ ​It​ ​is​ ​advisable​ ​to​ ​set​ ​a​ ​Bunsen​ ​burner​ ​to​ ​luminous​ ​flame​ ​prior​ ​to​ ​an​ ​experiment. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​Explain 3. The​ ​paper​ ​chromatography​ ​of​ ​a​ ​plant​ ​extract​ ​gave​ ​the​ ​following​ ​results: Solvent Number​ ​of​ ​spots X 6 Y 2 Z 3 (a)​ ​Which​ ​is​ ​the​ ​most​ ​suitable​ ​solvent​ ​for​ ​purifying​ ​the​ ​extract?​ ​Explain ​ ​(b)​ ​Ball​ ​pen​ ​cannot​ ​be​ ​used​ ​to​ ​mark​ ​solvent​ ​front​ ​in​ ​the​ ​above​ ​chromatography.​ ​Explain 4. Name​ ​the​ ​process​ ​which​ ​takes​ ​place​ ​when: ​ ​(a)​ ​Solid​ ​Carbon​ ​(Iv)​ ​Oxide​ ​(dry​ ​ice)​ ​changes​ ​directly​ ​into​ ​gas (b)​ ​A​ ​red​ ​litmus​ ​paper​ ​turns​ ​white​ ​when​ ​dropped​ ​into​ ​chlorine​ ​water (c)​ ​Propene​ ​gas​ ​molecules​ ​are​ ​converted​ ​into​ ​a​ ​giant​ ​molecule 5. A​ ​sample​ ​of​ ​copper​ ​turnings​ ​was​ ​found​ ​to​ ​be​ ​contaminated​ ​with​ ​copper​ ​(II)​ ​oxide.
The​ ​paper​ ​chromatography​ ​of​ ​a​ ​plant​ ​extract​ ​gave​ ​the​ ​following​ ​results: Solvent Number​ ​of​ ​spots X 6 Y 2 Z 3 (a)​ ​Which​ ​is​ ​the​ ​most​ ​suitable​ ​solvent​ ​for​ ​purifying​ ​the​ ​extract?​ ​Explain ​ ​(b)​ ​Ball​ ​pen​ ​cannot​ ​be​ ​used​ ​to​ ​mark​ ​solvent​ ​front​ ​in​ ​the​ ​above​ ​chromatography.​ ​Explain 4. Name​ ​the​ ​process​ ​which​ ​takes​ ​place​ ​when: ​ ​(a)​ ​Solid​ ​Carbon​ ​(Iv)​ ​Oxide​ ​(dry​ ​ice)​ ​changes​ ​directly​ ​into​ ​gas (b)​ ​A​ ​red​ ​litmus​ ​paper​ ​turns​ ​white​ ​when​ ​dropped​ ​into​ ​chlorine​ ​water (c)​ ​Propene​ ​gas​ ​molecules​ ​are​ ​converted​ ​into​ ​a​ ​giant​ ​molecule 5. A​ ​sample​ ​of​ ​copper​ ​turnings​ ​was​ ​found​ ​to​ ​be​ ​contaminated​ ​with​ ​copper​ ​(II)​ ​oxide. Describe how​ ​a​ ​sample​ ​of​ ​copper​ ​metal​ ​can​ ​be​ ​separated​ ​from​ ​the​ ​mixture 6. Copper​ ​(II)​ ​oxide​ ​and​ ​charcoal​ ​are​ ​black​ ​solids.​ ​How​ ​would​ ​you​ ​distinguish​ ​between​ ​the two​ ​solids? 7. a)​ ​What​ ​is​ ​chromatography? b)​ ​Give​ ​two​ ​applications​ ​of​ ​chromatography 8.
7. a)​ ​What​ ​is​ ​chromatography? b)​ ​Give​ ​two​ ​applications​ ​of​ ​chromatography 8. The​ ​two​ ​elements​ ​P​ ​and​ ​R​ ​were​ ​separately​ ​burned​ ​in​ ​air,​ ​the​ ​products​ ​gave​ ​the​ ​results ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​recorded​ ​in​ ​the​ ​table​ ​below: ELEMENTS​ ​ ​PHYSICAL STATE​ ​AT​ ​ROOM TEMPERATURE P​ ​SOLID R​ ​SOLID Physical​ ​states​ ​of​ ​products White​ ​solid​ ​powder only Colourless​ ​gases​ ​L​ ​and​ ​M Nature​ ​of​ ​solutions​ ​in​ ​water Basic L​ ​strongly​ ​acidic​ ​M​ ​slightly acidic (a)​ ​Suggest​ ​the​ ​identity​ ​of​ ​element​ ​R.​ ​……………………………………………..…….. (b)​ ​Describe​ ​how​ ​the​ ​nature​ ​of​ ​the​ ​solutions​ ​of​ ​the​ ​of​ ​the​ ​oxides​ ​were​ ​determined 9 The​ ​diagram​ ​below​ ​represents​ ​a​ ​paper​ ​chromatography​ ​for​ ​the​ ​three​ ​brands​ ​of​ ​soft​ ​drinks containing​ ​banned​ ​artificial​ ​food​ ​additives.
b)​ ​Give​ ​two​ ​applications​ ​of​ ​chromatography 8. The​ ​two​ ​elements​ ​P​ ​and​ ​R​ ​were​ ​separately​ ​burned​ ​in​ ​air,​ ​the​ ​products​ ​gave​ ​the​ ​results ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​recorded​ ​in​ ​the​ ​table​ ​below: ELEMENTS​ ​ ​PHYSICAL STATE​ ​AT​ ​ROOM TEMPERATURE P​ ​SOLID R​ ​SOLID Physical​ ​states​ ​of​ ​products White​ ​solid​ ​powder only Colourless​ ​gases​ ​L​ ​and​ ​M Nature​ ​of​ ​solutions​ ​in​ ​water Basic L​ ​strongly​ ​acidic​ ​M​ ​slightly acidic (a)​ ​Suggest​ ​the​ ​identity​ ​of​ ​element​ ​R.​ ​……………………………………………..…….. (b)​ ​Describe​ ​how​ ​the​ ​nature​ ​of​ ​the​ ​solutions​ ​of​ ​the​ ​of​ ​the​ ​oxides​ ​were​ ​determined 9 The​ ​diagram​ ​below​ ​represents​ ​a​ ​paper​ ​chromatography​ ​for​ ​the​ ​three​ ​brands​ ​of​ ​soft​ ​drinks containing​ ​banned​ ​artificial​ ​food​ ​additives. 4 1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​6 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​7 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​5 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​3 A B C BRANDS​ ​OF​ ​SOFT​ ​DRINKS A​ ​and​ ​C​ ​found​ ​to​ ​contain​ ​the​ ​banned​ ​artificial​ ​food​ ​additives.​ ​Which​ ​numbers​ ​indicate the ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​banned​ ​artificial​ ​food​ ​additives?
The​ ​two​ ​elements​ ​P​ ​and​ ​R​ ​were​ ​separately​ ​burned​ ​in​ ​air,​ ​the​ ​products​ ​gave​ ​the​ ​results ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​recorded​ ​in​ ​the​ ​table​ ​below: ELEMENTS​ ​ ​PHYSICAL STATE​ ​AT​ ​ROOM TEMPERATURE P​ ​SOLID R​ ​SOLID Physical​ ​states​ ​of​ ​products White​ ​solid​ ​powder only Colourless​ ​gases​ ​L​ ​and​ ​M Nature​ ​of​ ​solutions​ ​in​ ​water Basic L​ ​strongly​ ​acidic​ ​M​ ​slightly acidic (a)​ ​Suggest​ ​the​ ​identity​ ​of​ ​element​ ​R.​ ​……………………………………………..…….. (b)​ ​Describe​ ​how​ ​the​ ​nature​ ​of​ ​the​ ​solutions​ ​of​ ​the​ ​of​ ​the​ ​oxides​ ​were​ ​determined 9 The​ ​diagram​ ​below​ ​represents​ ​a​ ​paper​ ​chromatography​ ​for​ ​the​ ​three​ ​brands​ ​of​ ​soft​ ​drinks containing​ ​banned​ ​artificial​ ​food​ ​additives. 4 1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​6 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​7 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​5 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​3 A B C BRANDS​ ​OF​ ​SOFT​ ​DRINKS A​ ​and​ ​C​ ​found​ ​to​ ​contain​ ​the​ ​banned​ ​artificial​ ​food​ ​additives.​ ​Which​ ​numbers​ ​indicate the ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​banned​ ​artificial​ ​food​ ​additives? 10.
(b)​ ​Describe​ ​how​ ​the​ ​nature​ ​of​ ​the​ ​solutions​ ​of​ ​the​ ​of​ ​the​ ​oxides​ ​were​ ​determined 9 The​ ​diagram​ ​below​ ​represents​ ​a​ ​paper​ ​chromatography​ ​for​ ​the​ ​three​ ​brands​ ​of​ ​soft​ ​drinks containing​ ​banned​ ​artificial​ ​food​ ​additives. 4 1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​6 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​7 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​5 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​3 A B C BRANDS​ ​OF​ ​SOFT​ ​DRINKS A​ ​and​ ​C​ ​found​ ​to​ ​contain​ ​the​ ​banned​ ​artificial​ ​food​ ​additives.​ ​Which​ ​numbers​ ​indicate the ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​banned​ ​artificial​ ​food​ ​additives? 10. Without​ ​using​ ​any​ ​laboratory​ ​chemical,​ ​describe​ ​a​ ​simple​ ​laboratory​ ​experiment​ ​to distinguish between​ ​calcium​ ​hydrogen​ ​carbonate​ ​and​ ​sodium​ ​hydrogen​ ​carbonate 11.​ ​Substance​ ​Q​ ​has​ ​a​ ​melting​ ​point​ ​of​ ​15​o​C​ ​and​ ​boiling​ ​point​ ​of​ ​70​o​C.
10. Without​ ​using​ ​any​ ​laboratory​ ​chemical,​ ​describe​ ​a​ ​simple​ ​laboratory​ ​experiment​ ​to distinguish between​ ​calcium​ ​hydrogen​ ​carbonate​ ​and​ ​sodium​ ​hydrogen​ ​carbonate 11.​ ​Substance​ ​Q​ ​has​ ​a​ ​melting​ ​point​ ​of​ ​15​o​C​ ​and​ ​boiling​ ​point​ ​of​ ​70​o​C. (a)​ ​On​ ​the​ ​same​ ​axes,​ ​draw​ ​the​ ​melting​ ​point​ ​and​ ​boiling​ ​point​ ​graph​ ​for​ ​Q​ ​and​ ​the​ ​room ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​temperature ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​(b)​ ​State​ ​the​ ​physical​ ​state​ ​of​ ​substance​ ​Q​ ​at​ ​room​ ​temperature 12. Cooking​ ​oils​ ​comprise​ ​of​ ​a​ ​mixture​ ​of​ ​compounds​ ​which​ ​have​ ​a​ ​boiling​ ​point​ ​range ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​of​ ​23​o​C​ ​to​ ​27​o​C. (i)​ ​What​ ​evidence​ ​is​ ​then​ ​to​ ​support​ ​the​ ​statement​ ​that​ ​cooking​ ​oil​ ​is​ ​a​ ​mixture? (ii)Name​ ​another​ ​experimental​ ​technique​ ​that​ ​could​ ​be​ ​used​ ​to​ ​confirm​ ​your​ ​answer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​in​ ​part​ ​(i)​ ​above 13.
Cooking​ ​oils​ ​comprise​ ​of​ ​a​ ​mixture​ ​of​ ​compounds​ ​which​ ​have​ ​a​ ​boiling​ ​point​ ​range ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​of​ ​23​o​C​ ​to​ ​27​o​C. (i)​ ​What​ ​evidence​ ​is​ ​then​ ​to​ ​support​ ​the​ ​statement​ ​that​ ​cooking​ ​oil​ ​is​ ​a​ ​mixture? (ii)Name​ ​another​ ​experimental​ ​technique​ ​that​ ​could​ ​be​ ​used​ ​to​ ​confirm​ ​your​ ​answer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​in​ ​part​ ​(i)​ ​above 13. A​ ​form​ ​1​ ​student​ ​carried​ ​out​ ​the​ ​separation​ ​as​ ​shown​ ​in​ ​the​ ​set-up​ ​below:- ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​(i)​ ​ ​Identify​ ​the​ ​method​ ​above................................................................................. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​(ii)​ ​Give​ ​one​ ​of​ ​its​ ​disadvantages ​ ​ ​ ​ ​ ​ ​ ​ ​ ​(iii)​ ​Name​ ​a​ ​mixture​ ​which​ ​can​ ​be​ ​separated​ ​by​ ​the​ ​set-up​ ​above 14. What​ ​is​ ​meant​ ​by​ ​melting​ ​point​ ​and​ ​boiling​ ​point​ ​of​ ​a​ ​substance? 15.
​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​(ii)​ ​Give​ ​one​ ​of​ ​its​ ​disadvantages ​ ​ ​ ​ ​ ​ ​ ​ ​ ​(iii)​ ​Name​ ​a​ ​mixture​ ​which​ ​can​ ​be​ ​separated​ ​by​ ​the​ ​set-up​ ​above 14. What​ ​is​ ​meant​ ​by​ ​melting​ ​point​ ​and​ ​boiling​ ​point​ ​of​ ​a​ ​substance? 15. The​ ​apparatus​ ​below​ ​were​ ​used​ ​by​ ​a​ ​student​ ​to​ ​study​ ​the​ ​effect​ ​of​ ​heat​ ​on​ ​hydrated ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​copper​ ​II​ ​sulphate
(a)​ ​What​ ​is​ ​the​ ​role​ ​of​ ​the​ ​ice​ ​cold​ ​water…………… (b)​ ​Name​ ​liquid​ ​P………………………………………………………… (c)​ ​What​ ​observation​ ​is​ ​made​ ​in​ ​the​ ​boiling​ ​tube
17. The​ ​diagram​ ​below​ ​shows​ ​chromatograms​ ​of​ ​blood​ ​samples​ ​obtained​ ​from​ ​three​ ​athletes. One athlete​ ​used illegal​ ​drug to improve performance in competition. (a)​ ​Name​ ​the​ ​line​ ​marked​ ​ ​M …………………………………………………. (b)Identify​ ​the​ ​athlete​ ​who​ ​used​ ​illegal​ ​drug ……………... ………………………. 18.
​ ​ ​ ​ ​ ​ ​ ​ ​ ​Displacement​ ​reaction​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​………………………………………… 19. Give​ ​two​ ​reasons​ ​why​ ​a​ ​luminous​ ​flame​ ​is​ ​not​ ​used​ ​for​ ​heating​ ​purposes 20. Classify​ ​the​ ​following​ ​processes​ ​as​ ​chemical​ ​changes​ ​or​ ​physical​ ​changes ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​Process​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​physical​ ​or​ ​chemical ​ ​ ​ ​ ​ ​ ​ ​ ​ ​Neutralization​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​……………………………………… ​ ​ ​ ​ ​ ​ ​ ​ ​ ​Sublimation​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​……………………………………… ​ ​ ​ ​ ​ ​ ​ ​ ​ ​Fractional​ ​distillation​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​……………………………………….. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​Displacement​ ​reaction​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​………………………………………… 21. Give​ ​two​ ​reasons​ ​why​ ​a​ ​luminous​ ​flame​ ​is​ ​not​ ​used​ ​for​ ​heating​ ​purposes 22. State​ ​two​ ​criteria​ ​for​ ​determining​ ​the​ ​purity​ ​of​ ​a​ ​substance Substance Water Concentrated sulphuric(VI)acid Concentrated sodium​ ​hydroxide
Ethene Slightly soluble Soluble Insoluble Ammonia Very​ ​ ​soluble Very​ ​ ​soluble Very​ ​ ​soluble Hydrogen Slightly​ ​soluble Insoluble Insoluble 23.