CHEM UNIT 2 PAST PAP
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| What colour would phenolphthalein turn at the end-point in this titration? | show 🗑
|
||||
| show | A pipette.
🗑
|
||||
| show | 12.50 cm3.
🗑
|
||||
| Which of these metal hydroxides is the most soluble in water? | show 🗑
|
||||
| Which of these metals will give a lilac flame colour? | show 🗑
|
||||
| show | D 2-methylpentan-2-ol
🗑
|
||||
| Which of these statements about fluorine is not correct? | show 🗑
|
||||
| What is the oxidation number of oxygen in dioxygen difluoride, O2F2? | show 🗑
|
||||
| show | PCl3 and CO
🗑
|
||||
| Which intermolecular forces exist between molecules of ethoxyethane? | show 🗑
|
||||
| The following liquids all have the same number of electrons in each molecule. | show 🗑
|
||||
| Which one is likely to have the lowest boiling point? | show 🗑
|
||||
| Which of these is likely to be the best solvent for cyclohexanol? | show 🗑
|
||||
| show | Propane-1,2,3-triol.
🗑
|
||||
| What type of species forms when a bond breaks homolytically? | show 🗑
|
||||
| In the reaction between Ag+(aq) ions and Fe2+(aq) ions, what would be the effect of increasing the concentration of Ag+(aq) ions? Ag+(aq) + Fe2+(aq) | show 🗑
|
||||
| Which one of these reactions is not a disproportionation reaction? | show 🗑
|
||||
| show | they change their polarity when they vibrate.
🗑
|
||||
| show | 1 O H stretching in alcohols at 3750 − 3200 cm–1 2 C=O stretching in aldehydes at 1740 − 1720 cm–1 3 C=O stretching in ketones at 1700 − 1680 cm–1. 4 C=O stretching in carboxylic acids at 1725 − 1700 cm–1 -
🗑
|
||||
| show | To monitor whether all of the sample of propan-2-ol has been oxidized, you can look for.
🗑
|
||||
| State the reagents and conditions needed to convert the following halogenoalkanes into the named product. 1-bromobutane into butan-1-ol | show 🗑
|
||||
| show | Ammonia / NH3 (in ethanol) (1) Heat and pressure / heat in a sealed tube
🗑
|
||||
| show | (concentrated) Sodium hydroxide / potassium hydroxide / NaOH / KOH (1) (heat and)dissolved in ethanol.
🗑
|
||||
| Chloroethane can be prepared by reacting ethanol with PCl in the presence of concentrated S04 . Explain why a similar reaction using potassium iodide and concentrated sulfuric acid should not be used to prepare iodoethane. | show 🗑
|
||||
| show | Bromochlorodifluoromethane
🗑
|
||||
| show | Halogenoalkanes; Absorb heat from fire ,Prevent oxygen from reaching the fire/form a layer that excludes oxygen, Absorb free radicals in combustion propagation, Strength of C-F bond makes molecules, inert / strength of C-F bond makes it hard to break.
🗑
|
||||
| Suggest a reason why the scientific community still supports the use of fire retardants containing CF3CHF2. | show 🗑
|
||||
| show |
🗑
|
||||
| show |
🗑
|
||||
| 2Cu2+(aq) + 4I−(aq) → 2CuI(s) + I2(aq) | show 🗑
|
||||
| What happens to the Cu2+(aq) during this reaction? Justify your answer. | show 🗑
|
||||
| Indicator | show 🗑
|
||||
| The whole of the solution containing iodine was used in one titration. Explain how this affects the reliability of your answer to | show 🗑
|
||||
| This question is about boron and nitrogen compounds. Draw and name the shape of a boron trifluoride, BF3, molecule. Suggest the FBF bond angle. | show 🗑
|
||||
| Ammonia has the formula NH3. Its HNH bond angle is less than the FBF bond angle in boron trifluoride. Estimate the HNH bond angle in NH3. | show 🗑
|
||||
| show | 3 electron pairs around central B atom but 4 electron pairs around central N
🗑
|
||||
| show |
🗑
|
||||
| Name the strongest intermolecular force between BF3 molecules | show 🗑
|
||||
| show | Hydrogen bonds / H-bonds
🗑
|
||||
| show |
🗑
|
||||
| What is the oxidation number of nitrogen in ammonia, NH3? | show 🗑
|
||||
| The diagram below shows the distribution of molecular energies in the reaction at 750°C. On the same diagram, draw a curve to show the distribution at 500°C and explain what effect this change in temp would have on the rate of the reaction. | show 🗑
|
||||
| Curve with higher peak to left of 750°C peak (1) Smaller area under curve above Ea (1) Reaction rate slower as fewer particles have E ≥ Ea (so fewer successful collisions per second) | show 🗑
|
||||
| Explain how a catalyst speeds up the rate of a reaction. | show 🗑
|
||||
| The half-equation for the oxidation of ethanol is CH3CH2OH + H2O → CH3COOH + 4H+ + 4e- . to write a full equation for the overall reaction between acidified dichromate(VI) ions and ethanol. | show 🗑
|
||||
| show | To prevent the mixture heating too rapidly /prevent ethanol evaporating
🗑
|
||||
| show | Suitable flask & heat indicated Liebig Condenser ,Correct water flow
🗑
|
||||
| What colour would the mixture be after it was heated under reflux? | show 🗑
|
||||
| show | They have a (very) high boiling temperature / are ionic compounds
🗑
|
||||
| show | Fractional distillation / distil of water then distil of ethanoic acid / absorb water with anhydrous drying agent
🗑
|
||||
| would increasing the pressure have on the yield of ethanoic acid? Justify your answer. | show 🗑
|
||||
| show |
🗑
|
||||
| Suggest TWO reasons why it might be difficult, or undesirable, to produce ethanoic acid in industry by scaling up the laboratory process. - Energy costs to separate ethanoic acid from reaction mixture,Lab procedure is a batch process. | show 🗑
|
||||
| An alternative industrial process for the production of ethanoic acid is the oxidation,of butane using a transition metal catalyst at 150°C and 55–60 atm. 2C4H10(l) + 5O2(g) → 4CH3COOH(aq) + 2H2O(l) Evaluate the ‘ | show 🗑
|
||||
| Suggest TWO additional pieces of information that would help you make a more informed decision. | show 🗑
|
||||
| 2011: | show 🗑
|
||||
| Which of the following bond angles occur in a molecule of ethanol, C2H5OH? | show 🗑
|
||||
| show | Carbon dioxide, CO2
🗑
|
||||
| Which of the following molecules contains polar bonds but is not a polar molecule? | show 🗑
|
||||
| show | Hydrogen iodide, HI
🗑
|
||||
| Which list below shows the compounds in order of increasing boiling temperature? | show 🗑
|
||||
| Which of the following has the highest boiling temperature? | show 🗑
|
||||
| show | An element with a chloride which is liquid at room temperature.
🗑
|
||||
| show | excited electrons move from a higher to a lower energy level.This question is about the following compounds. Which compound gives a green colour in a flame test?
🗑
|
||||
| Which compound gives a lilac colour in a flame test and does not decompose on heating? | show 🗑
|
||||
| 20 cm3 of H2SO4 , concentration 0.25 mol dm–3, was neutralized in a titration with BaOH , concentration 0.50 mol dm–3. The equation for the reaction is Ba(OH)2(aq) + H2SO4(aq) → BaSO4(s) + 2H2O(l) | show 🗑
|
||||
| show | 10 cm3
🗑
|
||||
| During the titration, the barium hydroxide was added until it was present in excess. The electrical conductivity of the titration mixture | show 🗑
|
||||
| Which of the following trends occurs going down the elements in Group 2? | show 🗑
|
||||
| show | It forms a cream precipitate with silver nitrate solution.
🗑
|
||||
| show | disproportionation
🗑
|
||||
| Cl2(g) + 2Na(s) → 2NaCl(s) | show 🗑
|
||||
| NaCl(s) + H2SO4(l) → HCl(g) + NaHSO4(s) | show 🗑
|
||||
| When chloroethane is heated with a concentrated solution of potassium hydroxide in ethanol, the reaction which occurs is | show 🗑
|
||||
| Elimination. | show 🗑
|
||||
| Chloroethane reacts with aqueous potassium hydroxide solution, producing ethanol as the organic product. | show 🗑
|
||||
| show | a nucleophile.
🗑
|
||||
| show |
🗑
|
||||
| Write an equation for this reaction.. | show 🗑
|
||||
| show | Mg2+ / Magnesium ion smaller or fewer electron shells / greater charge density (1)OR Magnesium ion has same charge (as calcium ion) but is smaller (1) Causes more polarisation /distortion of nitrate/ anion (electron clouds) / N―O (bond)(1)
🗑
|
||||
| OR MgO produced has stronger lattice (1) OR production of MgO is more exothermic (1) OR reverse argument based on Ca2+ | show 🗑
|
||||
| show | 2NaNO3 → 2NaNO2 + O2.
🗑
|
||||
| Scientists have found that the bonds between nitrogen and oxygen in the nitrate ion are all the same length. Is the student’s suggestion supported by this evidence? Explain your answer. | show 🗑
|
||||
| show | Goes darker (brown) (1) Goes browner. Equilibrium moves in the endothermic direction (1) OR Equilibrium moves left as forward reaction is exothermic (1) Equilibrium moves left to counteract addition of heat.
🗑
|
||||
| Explain why an equilibrium mixture of these gases eventually becomes paler in colour when the pressure on it is increased. | show 🗑
|
||||
| Use the distributions to explain why gases react faster when the temperature is increased. | show 🗑
|
||||
| When Cl is added to a solution containing Br or I2 ions, a colour . change occurs. What solvent add to mixture to confirm identity of halogen | show 🗑
|
||||
| Give the result for the test with this solvent in a reaction in which bromine is produced. | show 🗑
|
||||
| show | Oxidation number of S in H2SO4 =(+)6, Oxidation number of S in SO2 =(+)4 (1) Oxidation number had decreased (1)
🗑
|
||||
| State TWO observations, which would differ from those with potassium bromide, when potassium iodide reacts with concentrated sulfuric acid. | show 🗑
|
||||
| One product of the reaction with potassium iodide is hydrogen sulfide, H2S. How does this show that iodide ions are more powerful reducing agents than bromide ions? | show 🗑
|
||||
| Oxidation number of S has reduced more / to –2 (in H2S) (1) OR | show 🗑
|
||||
| show |
🗑
|
||||
| show |
🗑
|
||||
| show |
🗑
|
||||
| Give ONE reason why it could be considered more ethical to supply free fluoride tablets than add fluoride to the water. | show 🗑
|
||||
| show |
🗑
|
||||
| Butan-1-ol and three other alcohols, X, Y and Z, are isomers. Give TWO make when any one of the alcohols reacts with sodium. | show 🗑
|
||||
| show |
🗑
|
||||
| Give the molecular formula of the organic product of the reaction. | show 🗑
|
||||
| show | O━H absorption / peak in 2-methylpropanoic acid / No O━H absorption / peak in Q ALLOW C━O absorption / peak in 2-methylpropanoic acid / No C━O absorption / peak in Q One of the isomers, X, Y or Z can be converted to 2-chlorobutane.
🗑
|
||||
| show | PCl5 / PCl3 / conc HCl / SOCl2 / mixture of NaCl + H2SO4 / mixture of KCl + H2SO4.
🗑
|
||||
| show |
🗑
|
||||
| show | (ALLOW intermolecular forces) stronger in water (1) I2(aq) + 2S2O3 2–(aq) → 2I–(aq) + S4O6 2–(aq)
🗑
|
||||
| show | Water has 2 hydrogen bonds per molecule (on average) whereas ethanol only has 1 (1) ALLOW Water has more hydrogen bonds (per molecule) than ethanol Needs more energy to break H bonds in water (so less soluble) / H bonding
🗑
|
||||
| show | Starch (solution)
🗑
|
||||
| The amount of sulfur dioxide in the atM can be measured by passing a known volume of air through iodine solution | show 🗑
|
||||
| .. | show 🗑
|
||||
| show | 12.60 cm3 of sodium thiosulfate, concentration 0.100 mol dm–3.
🗑
|
||||
| How many moles of iodine were present in the solution of the iodine at the start of the experiment? | show 🗑
|
||||
| How many moles of iodine remained in the solution at the end of the experiment? | show 🗑
|
||||
| Calculate the number of moles of iodine which reacted with the sulfur dioxide, and hence the number of moles of sulfur dioxide in 100 m3 of air. | show 🗑
|
||||
| show | Mass SO2 in 100 m3 =(64.1 x 3.70 x 10-4 ) (1) Mass SO2 in 1 m3 = 64.1 x 3.70 x 10-4 /100 = 237(.2) x 10-6 g = 2.37 x 10-4g (1) (= 237.2 / 237 / 240 μg)
🗑
|
||||
| show | Improved because titration may be repeated /averages could be taken ALLOW Smaller titration reading so greater (%) error
🗑
|
||||
| show | Larger titration reading (1) So smaller (%)error in titration reading (1)OR Smaller mass of sodium thiosulfate used to make solution (1) So greater %) error in the mass measurement (1) 150 m3 of air was passed through the iodine.
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
ufuoma
Popular Chemistry sets