Your Virtual Mentor| Question | Options |
|---|---|
| Copper(II) sulfate crystals are separated from sand using the four processeslisted below.In which order are these processes used? | 1st filtering 2nd dissolving 3rd crystallising 4th evaporating , 1st filtering 2nd di |
| A drop of liquid bromine is placed in the bottom of a gas jar. Brown fumes of bromine vapour slowly spread through the covered gas jar.Why does this happen? | Bromine vapour is less dense than air., Bromine molecules and the molecules in air are always movin |
| What is the mass of oxygen contained in 72 g of pure water? [Relative atomic masses: H = 1; O = 16] | 16 g , 32 g , 64 g , 70 g |
| A student tested a solution by adding aqueous sodium hydroxide. A precipitate was not seen because the reagent was added too quickly.What could not have been present in the solution? | Al 3+, Ca2+, NH4+, Zn2+ |
| Which molecule has the largest number of electrons involved in covalent bonds? | C2H4 , CO2, CH3OH , N2 |
| In which of the following is there a lattice of positive ions in a ‘sea of electrons’? | liquid potassium chloride, sand, solid graphite, solid magnesium |
| Which statement about both chlorine atoms and chloride ions is correct? | They are chemically identical., They are isotopes of chlorine., They have the same number of proton |
| Element X has the electronic structure 2,8,5. Element Y has the electronic structure 2,8,7. What is the likely formula of a compound containing only X and Y? | XY3 , X2Y3 , X3Y , X3Y2 |
| A covalent bond is formed by | electron sharing between metals and non-metals., electron sharing between non-metals., electron tra |
| The equation for the reaction between calcium carbonate and hydrochloric acid is shown.CaCO3(s) + 2HCl (aq) ? CaCl 2(aq) + H2O(l) + CO2(g) How many moles of calcium carbonate will give 24 cm3 of carbon dioxide when reacted with an excess of the acid? | 1 mol, 0.1 mol, 0.01 mol, 0.001 mol |
| The empirical formula of a liquid compound is C2H4O. To find the empirical formula, it is necessary to know the | density of the compound., percentage composition of the compound., relative molecular mass of the c |
| in the reaction between zinc and hydrochloric acid. 1 increase in concentration of the acid 2 increase in particle size of the zinc 3 increase in pressure on the system 4 increase in temperature of the system Which pair of changes will increase the rate of reaction? | 1 and 2, 1 and 4 , 2 and 3 , 3 and 4 |
| The equation shows what happens in a redox reaction between iron(II) chloride and chlorine gas. 2FeCl 2 + Cl 2 ? 2FeCl 3 Which equation describes the reduction process in this reaction? | 2Cl – ? Cl 2 + 2e–, Cl 2 + 2e– ? 2Cl –, Fe2+ ? Fe3+ + e–, Fe3+ + e– ? Fe2+ |
| Which acid and base react together to produce an insoluble salt? | hydrochloric acid and sodium hydroxide, nitric acid and calcium oxide, sulfuric acid and barium hy |
| Carbon and silicon are both in Group IV of the Periodic Table. Which statement is correct for both carbon dioxide and silicon dioxide? | They are acidic oxides., They are readily soluble in water., They contain ionic bonds., They have |
| Which calcium compound does not increase the pH of acidic soils? | calcium carbonate, calcium hydroxide, calcium oxide, calcium sulfate |
| Which deduction about the element astatine, At, can be made from its position in Group VII? | It forms covalent compounds with sodium., It is a gas., It is displaced from aqueous potassium ast |
| Which pair of properties are both correct for a typical transition element? | forms coloured compounds soluble in water, high density has variable oxidation states, lo |
| What happens when zinc foil is placed in an aqueous solution of copper(II) sulfate? | Copper(II) ions are oxidised., There is no reaction., Zinc atoms are oxidised., Zinc sulfate is pr |
| Which element can only be extracted from its ore using electrolysis? | calcium, copper, lead, silver |
| Scrap iron is often recycled. Which reason for recycling is not correct? | It reduces the amount of pollution at the site of the ore extraction., It reduces the amount of wast |
| Aluminium is higher than copper in the reactivity series so the following displacement reaction should be feasible. 2Al (s) + 3CuSO4(aq) ? Al 2(SO4)3(aq) + 3Cu(s) The reaction does not take place at room temperature. What is the reason for this? | Aluminium has an inert coating all over it., The compound aluminium sulfate does not exist., The re |
| 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 o |
| When a volcano erupts, which gas is produced in significant amounts? | carbon monoxide, chlorofluorocarbons, methane, sulfur dioxide |
| Which statement about ethanoic acid is correct? | It contains three carbon atoms per molecule., It contains five hydrogen atoms per molecule., It is |
| Which bond is present in both nylon and Terylene? | C – O , C = O , N – C , N – H |
| Compounds X and Y are both alkanes. Compound X has a higher boiling point than compound Y. What could be the formulae of compounds X and Y? | C8H16 C9H18, C8H18 C9H20, C9H18 C8H16, C9H20 C8H18 |
| With which substance will ethene react to form more than one product? | bromine, hydrogen, oxygen, steam |
| When a compound X is reacted with sodium carbonate, carbon dioxide gas is evolved. What could be the formula of compound X? | C2H5CO2CH3, C3H7CO2H , CH3CO2C2H5 , C4H9OH |