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WHICH GAS HAS THE SLOWEST RATE OF DIFFUSION ? ammonia ,NH3, methane ,CH4, oxygen O2, Nitrogen N2
An excess of calcium hydroxide is added to an acidic soil what happens to the pH of the soil ? increase ,7, increase ,10, decrease ,7, decrease ,5
Which test cold be used to show that a sample of water is pure ? it freezes at exectly 0° C, it turn cobalt (II) chloride paper pink, when it evaporates it leaves no
Hydrogen can form both ion and H-ions which statement about these two ions is correct ? An H + ion has no electron in its first shell, An H + ion has more protrons then an H-ions , An H- i
Substance X conducts electricity when in the solide state X reacts with hydrochloric acid which substance could X be ? Copper (II) oxide, Sillion (IV) oxide, Sodium chloride, Zinc
Rubidium is in group I and bromine is in group VII of the Periodic table how is acompound formed between rubidium and bromine ? Each atom of bromine shares an electron with an atom of rubidium, Each atom of bromine shares a pair
2 dm3 of aqueous sodium hydroxide of concentration 5 mole/dm3 were required for an experiment how many moles of sodium hydroxide were needed to make up this solution? 2.5, 5, 7, 10
An 8 g sample of oxygen atom contains the same number of atom as 16 g of element X what is the relative atomic mass A opf X : 4, 8, 16, 32
Which pair of substance act as reducing agent in the blast furance ? Carbon and oxygen , Carbon monoxide and carbon dioxide, carbon and carbon monoxide, carbon dioxide
The equation below shows an exothermic reaction Mg(s) + 2 HCl(aq) ? MgCl2(aq) + H2(g) Which statement about this exothermic reaction is not correct ? Magnesium chloride is soluble in water, magnesium is above hydrogen in the reactivity series, one mo
which statement about conduction of electricity is correct ? Electricity is conducted in aqueous solution by electron, Electricity is conducted in a metal wire b
Which change is an example of oxidation ? Chloride ion to chlorine atom, Copper (II) ion to Copper atom, iron (III) ions to iron (II) ions,
Which cation on reaction with aqueous sodium hydroxide forms a precipitate that dissolves in excess sodium hydroxide ? Ca2+, CU2+, Fe3+, Zn2+
Which of the following is a reaction of dilute sodium hydroxide ? it react with ammonium chloride to produced ammonia, it react with calcium carbonate to produced ca
The equation for one method of making copper carbonate is shown below CUSO4 +Na2CO3 ? Na2CO3 + Na2SO4 THE REACTION IS AN EXAMPLE OF : neutralisation, oxidation and reduction, Precipitation, synthesis
A lump of element X can be cut by a knife .During its reaction with water X floats and melts what is X ? Calcium, Copper, Magnesium, Potassium
Which deduction about the element astatine at can be made from its position in Group VII ? it form covalent compound with sodium, it is displaced from aqueous potassium astatide,Kat by chlori
Which atom has same electron configuration as the strontium ion ? Calcium, krypton, rubidium, selenium
Rubidium is in group I of the Periodic table what are properties of rubidium chloride ? RbCl ,70, insoluble, RbCl ,700, soluble, RbCl2 ,70, soluble, RbCl2 ,700, insoluble
iron pipes corrode rapidly when exposed to sea water which metal when attached to the iron would not offer protection aainst corrosion ? Aluminium, Copper, Magnesium, Zinc
Metal carbonates decompose when heated. Which carbonate is most stable to heat? calcium carbonate, copper(II) carbonate, lead(II) carbonate, zinc carbonate
From your knowledge of the manufacture of both aluminium and iron, what is the order of chemical reactivity of aluminium, carbon and iron towards oxygen? aluminium, carbon ,iron, aluminium, iron ,carbon, carbon, aluminium, iron, carbon, iron ,aluminium
Element R reacts with oxygen to form a gas, T. T changes the colour of damp litmus paper from blue to red. T is used to kill bacteria in the preservation of dried fruit. What is R? carbon, chlorine, nitrogen, sulphur
The gases coming from a car’s exhaust contain oxides of nitrogen. How are these oxides formed? Nitrogen reacts with carbon dioxide., Nitrogen reacts with carbon monoxide., Nitrogen reacts with ox
The table shows pollutants and their possible effects. Which line is not correct? CFCs ,cause destruction of the ozone layer, CH4, forms photochemical smog, CO, is poisonous to huma
In the polymerisation of ethene to form poly(ethene), which of the following does not change? boiling point, density, empirical formula, molecular mass
In which pair of macromolecules are the linkages the same? fats and proteins, nylon and fats, nylon and proteins, proteins and Terylene