Free School Management System
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√1 for labeling C and D
√1 For showing correct electron distribution.
(e). The metallic bond in M is stronger that in √1L because M has more valence electrons.√1
(f). Add water to the mixture √½. Stir/shake the mixture√½. Filter the mixture to obtain the filtrate and the residue√½. Dry the mixture to obtain lead (ii) sulphate. Evaporate or crystallize the filtrate to obtain the sulphate of R.√1
(a). When boiled√1 calcium hydrogen carbonate or magnesium hydrogen decomposes to calcium carbonate which precipitates.√1
(b). (i). on the graph paper.
(ii). at 700 = 135/100g of H2O.√1
(iii). At 800, it is saturated by 180g Salt to be added = 180g -100g =80g√1
(iv). In fractional crystallization i.e. separation of common salt(NaCl) from Na2CO3 in salty waters. (c).
(a). Products√1 i.e forward reaction which increases the concentration of the reactants.√
(b). Because th products are being formed at a higher rate hence t he forward reaction is faster but soon the reverse reaction and forward reaction become at equilibrium.
(c). Point of equilibrium.
(b). Gases – cooking/gas cookers/laborating gas.
Petrol –Fuels in petrol engines
Kerosene –Domestic use/fuels for jet engines
Lubricating oils – use for smooth running of engine parts.
Bitumen –Tarmacking roads;
(c). (i). Catalytic cracking – breaking of long chain.Allcanes by passing them over a catalyst at high temperature of about 4000C -5000C √1
(ii). Thermal cracking –breaking of the carbon bonds in the long chain alkanes
At high temperature of 4000C -7000C to form shart chain allcanes and alkenes.
(d). (i). A - ethene√½
(iii). E – water√½
(f). Step I: Dehydration √
Step II: Addition reaction
(b). –Hydrochloric acid
(d). –Lead (II) carbonate reacts to form lead chloride which is insoluble and will Prevent further reaction.
(b). Lead (II) Oxide when heated is orange in colour, changes to form grey beads/grey Solid is observed.
(c). Potassium hydroxide solution/solution hydroxide soloution.
-To absorb CO2 formed during the reaction.
(ii). During heating, brown gas is observed, an orange residue formed which turns yellow on cooling.
(iii). Because lead (ii) nitrate is not hydrated.
(iv). By bringing a glowing splint in the gas jar, it relights.
(b). (i). Nitrogen tetraoxide.
(a). (i). Reagent –chlorine gas
(b). Potassium permanganate/manganese (iv) oxide lead (iv) oxide. Accept
(c). (I). To remove all oxygen or air which would form iron(iii) oxide.
(II). CaO absorbs both Cl2 and moisture CaCl2 can only absorb moisture.
(III). It sublimes or changes directly form solid to gas.
Any correct equation award √1 ignore state symbols
(a). The reaction starts then stops after some time since calcium reacts with sulphuric acid to form CaSO4 which is an insoluble salt.
(b). (i). Add anhydrous Copper
(ii) sulphate, changes from white to blue /add anhydrous cobalt (ii) chloride changes from blue to pink.
(ii). By testing its boiling point, boils at 1000C at sea level.
(ii). -Good teeth borne formation
-Good taste for drinking
-Good for brewing alcohols