IBChemistry: SLDPTopic Questions1. Stoichiometric Relationships1.2 Reacting Masses & Volumes

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First teaching 2014

Last exams 2024

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Reacting Masses & Volumes (DP IB Chemistry: SL)

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1.2 Reacting Masses & Volumes

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1.2 Reacting Masses & Volumes

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11 mark

When calcium carbonate is heated it decomposes according to the following equation

CaCO3 (s)  → CaO(s) +CO2(g)

If 6.00g of calcium carbonate is heated and produces 2.73g of calcium oxide, what is the percentage yield of calcium oxide? ( Mr CaCO3 = 100; CaO = 56)

  • fraction numerator 56 space cross times space 6.00 space cross times space 100 over denominator 2.73 end fraction

  • fraction numerator 2.73 space cross times space 100 space cross times space 100 over denominator 56 space cross times space 6.00 end fraction

  • fraction numerator 56 space cross times space 6.00 space cross times space 100 over denominator 2.73 space cross times space 100 end fraction

  • fraction numerator 2.73 space cross times space 100 over denominator 56 space cross times space 6.00 end fraction

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21 mark

Hydrogen and chlorine react according to the following equation

                                          H2(g)  + Cl2(g) → 2HCl(g)

When 1.5 moles of chlorine reacts with 2.0 moles of hydrogen, what will be the result?

  • 3.5 mol of HCl

  • 1.5 mol of HCl  and 0.5 mol of H2

  • 2.0 mol of HCl  and 0.5 mol of Cl2

  • 3.0 mol of HCl and 0.5 mol of H2

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31 mark

25.0 cm3 of hydrochloric acid solutions reacts with 36.2 cm3 of 0.225 mol dm-3 sodium hydroxide solution. The concentration of the acid is

  • fraction numerator 36.2 space cross times space 0.225 over denominator 25.0 end fraction

  • fraction numerator 25.0 space cross times space 0.225 over denominator 36.2 end fraction

  • fraction numerator 25.0 space cross times space 0.225 over denominator 1000 space cross times space 36.2 end fraction

  • fraction numerator 36.2 space cross times space 0.225 over denominator 1000 space cross times space 25.0 end fraction

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41 mark

Which amount of the following substances contains the smallest quantity of ions?

  • 2 mol of KOH  

  • 1 mol of NH4Br

  • 2 mol of MgCl2

  • 1 mol of Fe2O3

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51 mark

A solution of sodium chloride is made by adding 300 cm3 of water to a flask containing 200 cm3 of 0.50 mol dm-3 sodium chloride. What is the concentration of the resulting solution?

  • 0.05 mol dm-3   

  • 0.1 mol dm-3 

  • 0.2 mol dm-3 

  • 0.3 mol dm-3 

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61 mark

What is the number of molecules in 500 cm3 of oxygen under standard conditions?

  • 6.02 x 1023 x 0.5

  • 6.02 x 1023 x 500

  • fraction numerator 22.7 over denominator 0.5 end fraction space cross times space 6.02 space cross times space 10 to the power of 23

  • fraction numerator 0.5 over denominator 22.7 end fraction space cross times space 6.02 space cross times space 10 to the power of 23

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71 mark

For an ideal gas at constant pressure and temperature, which diagram shows the correct graph of pV against n?1-2-e-q7-ib-chemistry-mcqs

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    81 mark

    The Mr value of a gas can be calculated from the ideal gas equation.

    Which expression will give the value of Mr for a sample of a gas of mass m in grams?

    • Mr equals space mRT over pV

    • Mr space equals space pVRT over straight m

    • Mr space equals space mpV over RT

    • Mr space equals space pV over mRT

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    91 mark

    Which of the following least resembles an ideal gas at room temperature?

    • helium

    • ammonia

    • carbon dioxide

    • hydrogen

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    101 mark

    The ideal gas equation below summarises the gas laws.

                                  pV = nRT

    Which statement below is correct?

    • there exist intermolecular forces of attraction between gas molecules  

    • ideal gas molecules will collide inelastically upon impact with each other 

    • one mole of an ideal gas occupies the same volume under the same conditions of temperature and pressure 

    • the volume of a given mass of an ideal gas is doubled if its temperature is raised from 25oC to 50oC 

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    11 mark

    A periodic table is needed for this question

    A 2.27 dm3 sample of nitrogen gas, measured under standard conditions, reacted with a large excess volume of hydrogen gas to produce ammonia. Only 20.0% of the nitrogen gas reacted to produce ammonia.

    What mass of ammonia was made?

    • 0.20 g

    • 0.34 g

    • 0.68 g

    • 1.36 g

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    21 mark

    A periodic table is needed for this question 

    Excess aqueous cold sodium hydroxide is reacted with 0.10 mol of chlorine gas, Cl2. One of the products is a compound of sodium, oxygen and chlorine.

    What mass of the product is formed?

    • 3.54 g

    • 7.44 g

    • 14.8 g

    • 26.6 g

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    31 mark

    A periodic table is needed for this question

    When heated, anhydrous magnesium nitrate, Mg(NO3)2, will decompose into magnesium oxide and a mixture of gases shown in the following equation

    2Mg(NO3)2(s) → 2MgO(s) + 4NO2(g) + O2(g)

    1.48 g of anhydrous magnesium nitrate is heated until no further reaction takes place.

    What mass of nitrogen dioxide is produced?

    • 0.92 g

    • 0.46 g

    • 1.48 g

    • 1.84 g

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    41 mark

    A periodic table is needed for this question

    A hydrocarbon, X, was burned in excess oxygen to give carbon dioxide and water as the only products. 0.1mol of X produced 9.08dm3 of carbon dioxide at standard conditions.

    What is the molecular formula of X?

    • CH4

    • C2H6

    • C3H8

    • C4H10

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    51 mark

    A periodic table is needed for this question

    A Group II metal of mass 0.65 g reacted with 606.9 cm3 of oxygen at 273 K and 100kPa pressure, to form an oxide which contains O2- ions.

    The molar mass of the metal is found using which of the following calculations?

    • fraction numerator 22.7 space cross times space 0.65 over denominator 606.9 end fraction

    • fraction numerator 22.7 space cross times space 1000 space cross times space 0.65 over denominator 606.9 end fraction

    • fraction numerator 606.9 cross times space 1000 space cross times space 0.65 over denominator 22.7 end fraction

    • fraction numerator 22.7 space cross times space 1000 space cross times space 606.9 over denominator 0.65 end fraction

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    61 mark

    A periodic table is needed for this question

    Solid fertilisers often contain the elements N, P and K in a ratio of 20 g : 30 g : 10 g per 100 g of fertiliser. It is recommended that the fertiliser is used at 14 g of fertiliser per 5 dm3 of water.

    What is the concentration of nitrogen atoms in the solution?

    • 0.02 mol dm-3

    • 0.03 mol dm-3

    • 0.04 mol dm-3

    • 0.05 mol dm-3

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    71 mark

    An experiment is conducted to calculate the Mr of an unknown gas of known mass.

    Measurements of pressure, volume and temperature are taken during the experiment.

    Which conditions of temperature and pressure would give the most accurate value of Mr?

     

    pressure

    temperature

    A

    low

    high

    B

    low

    low

    C

    high

    high

    D

    high

    low

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      81 mark

      0.96 g of hydrogen gas is contained in a sealed vessel of volume of 7.0 × 10−3 m3 at a temperature of 303 K.

      Assume the gas behaves as an ideal gas.

      What is the pressure of the vessel in Pa?

      • fraction numerator 2.02 space cross times space 7.0 space cross times space 10 to the power of negative 3 end exponent over denominator 0.96 space cross times space 8.314 space cross times space 303 end fraction

      • fraction numerator 0.96 space cross times space 8.314 space cross times 303 over denominator 2.02 space cross times space 7.0 space cross times space 10 to the power of negative 3 end exponent end fraction

      • fraction numerator 0.96 space cross times space 8.314 space cross times space 303 over denominator 7.0 space cross times space 10 to the power of negative 3 end exponent end fraction

      • fraction numerator 0.96 space cross times space 8.314 space cross times space open parentheses 303 space plus space 273 close parentheses over denominator 2.02 space cross times space 7.0 space cross times space 10 to the power of negative 3 end exponent end fraction

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      91 mark

      A 5370 cm3 sample of oxygen is measured at a temperature of 60°C. The pressure measured was 103,000 Pa.

      Assume the gas behaves as an ideal gas.

      What is the mass of the sample of oxygen?

      • fraction numerator 103000 space cross times space 0.00537 space cross times space 32.00 over denominator 8.314 space cross times space 60 end fraction

      • fraction numerator 103000 space cross times space 0.00537 space cross times space 32.00 over denominator 8.314 space cross times space 333 end fraction

      • fraction numerator 103 space cross times space 0.00537 space cross times space 32.00 over denominator 8.314 space cross times space 333 end fraction

      • fraction numerator 103000 space cross times space 5370 space cross times 32.00 over denominator 8.314 space cross times space 333 end fraction

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      101 mark

      A sample of chlorine gas with a of mass 5.35 g has a volume of 1.247 × 10-3 m3 at a pressure of 1.00 × 105 Pa.

      Assuming that the gas acts as an ideal gas, what is the temperature of the gas in K?

      • fraction numerator 5.35 space cross times space 1.0 space cross times space 1.247 over denominator open parentheses 70.90 space cross times space 8.314 close parentheses end fraction

      • fraction numerator 5.35 space cross times space open parentheses 1.0 space cross times 10 to the power of 5 close parentheses space cross times space open parentheses 1.247 space cross times space 10 to the power of negative 3 end exponent close parentheses over denominator open parentheses 8.314 close parentheses end fraction

      • fraction numerator 5.35 space cross times open parentheses 1.0 space cross times space 10 to the power of 5 close parentheses space cross times space open parentheses 1.247 space cross times space 10 to the power of negative 3 end exponent close parentheses over denominator open parentheses 70.90 space cross times space 8.314 close parentheses end fraction

      • fraction numerator 70.90 space cross times space open parentheses 1.0 space cross times 10 to the power of 5 close parentheses space cross times space open parentheses 1.247 space cross times space 10 to the power of negative 3 end exponent close parentheses over denominator open parentheses 5.35 space cross times space 8.314 close parentheses end fraction

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      111 mark

      A bubble travelled up from the sea bed to the surface. Just below the surface of the sea the bubble had a volume of 200 cm3 at a pressure of 101 kPa. The temperature at the surface is the same as at the sea bed.

      The pressure at the sea bed is 2020 kPa. 

      What is the volume of the bubble at the sea bed?

      • 10 cm3

      • 200 cm3

      • 100 cm3

      • 1000 cm3

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      121 mark

      Sodium reacts with water in the equation below.

      2Na(s)  +  2H2O(l)  →  2NaOH(aq)  +  H2(g)

      Which mass of sodium reacts with water to produce 960 cm3 of hydrogen gas at 100kPa and 20oC?

      • fraction numerator 8.314 space cross times space 293 over denominator 100000 space cross times space 0.00096 space cross times space 2 space cross times space 22.99 end fraction

      • fraction numerator 100000 space cross times space 0.00096 space cross times space 2 space cross times space 22.99 over denominator 8.314 space cross times space 293 end fraction

      • fraction numerator 100000 space cross times space 960 space cross times space 2 space cross times space 22.99 over denominator 8.314 space cross times space 293 end fraction

      • fraction numerator 100000 space cross times space 0.00096 space cross times space 22.99 over denominator 8.314 space cross times space 293 end fraction

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      131 mark

      When a sample of a gas is compressed at room temperature from 101kPa to 300 kPa, its volume changes from 50.0 cm3  to 17.5 cm3.

      Which statement best describes why this happens?

      • the gas is behaving ideally  

      • the gas behaves non-ideally 

      • gas is absorbed on to the vessel walls

      • the gas partially liquifies  

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      141 mark

      A periodic table is needed for this question

      What mass of methane, CH4, would occupy a volume of 3 dm 3 at 25oC and 100 kPa pressure?

      • fraction numerator 100000 space cross times space 3 space cross times space 16.05 over denominator 8.314 space cross times space 298 end fraction

      • fraction numerator 100 space cross times space 0.003 space cross times space 16.05 over denominator 8.314 space cross times space 298 end fraction

      • fraction numerator 100000 space cross times space 0.003 space cross times space 16.05 over denominator 8.314 space cross times space 25 end fraction

      • fraction numerator 100000 space cross times space 0.003 space cross times space 16.05 over denominator 8.314 space cross times space 298 end fraction

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      151 mark

      Which expression gives the pressure exerted by 1.5 ×10-2 mol of carbon dioxide in a container of volume 2 dm-3 at 275oC?

      • fraction numerator open parentheses 1.5 space cross times space 10 to the power of negative 2 end exponent close parentheses space cross times space 8.31 space cross times space 275 over denominator 2 space cross times space 10 to the power of negative 6 end exponent end fraction

      • fraction numerator open parentheses 1.5 space cross times space 10 to the power of negative 2 end exponent close parentheses space cross times space 8.31 space cross times space open parentheses 275 space plus space 273 close parentheses over denominator 2 space cross times space 10 to the power of negative 6 end exponent end fraction

      • fraction numerator open parentheses 1.5 space cross times space 10 to the power of negative 2 end exponent close parentheses space cross times space 8.31 space cross times open parentheses 275 space plus 273 close parentheses over denominator 2 space cross times space 10 to the power of negative 3 end exponent end fraction

      • fraction numerator open parentheses 1.5 space cross times space 10 to the power of negative 2 end exponent close parentheses space cross times space 8.31 space cross times space 275 over denominator 2 space cross times space 10 to the power of negative 3 end exponent end fraction space

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      11 mark

      A periodic table is needed for this question

      When a 1.00 g sample of carbon is burned in a limited supply of oxygen, 0.72 g of the carbon combusts to form CO2 and 0.28 g of the carbon combusts to form CO.

      These gases were passed through excess NaOH (aq) which absorbs the CO2, but not the CO. The remaining gas was then dried and collected.

      Assuming that all gas volumes were taken at 25˚C and 100 kPa pressure, what was the volume of gas at the end of the reaction? (Molar Volume of a gas at stp = 22.7 dm3)

      • 2.27 dm3

      • 227 cm3

      • 5.29 dm3

      • 529 cm3

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      21 mark

      A periodic table is needed for this question

      Chicken eggs are made up of 5% by mass of egg shell. The average egg has a mass of 50 g.

      Assume that chicken eggshell is pure calcium carbonate. 

      How many complete chicken’s egg shells would need to neutralise 50 cm3 of 2.0 mol dm-3 ethanoic acid?

      • 4

      • 3

      • 2

      • 1

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      31 mark

      A periodic table is needed for this question

      When a sample of potassium oxide, K2O, is dissolved in 250 cm3 of distilled water, 25 cm3 of this solution is titrated against sulfuric acid with a concentration of 2.00 mol dm-3. Complete neutralisation takes place with 15 cm3 of sulfuric acid.

      What is the mass of the original sample of potassium oxide dissolved in 250 cm3 of distilled water?

      • fraction numerator 0.015 space cross times space 250 space cross times space 94.20 over denominator 25 end fraction

      • fraction numerator 2.00 space cross times space 0.015 space cross times space 94.20 over denominator 25 end fraction

      • fraction numerator 2.00 space cross times space 0.015 space cross times space 250 space cross times space 94.20 over denominator 25 end fraction

      • fraction numerator 2.00 space cross times space 0.015 space cross times space 25 space cross times space 94.20 over denominator 250 end fraction

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      41 mark

      A periodic table is needed for this question

      Iron and chromium can be made into an alloy called ferrochrome. Ferrochrome can be dissolved in dilute sulfuric acid to produce FeSO4 and Cr2(SO4)3. The FeSO4 reacts with acidified K2Cr2O7 as shown in this equation:

                          14H+ + 6Fe2+ + Cr2O72- →  2Cr3+  +  6Fe3+ + 7H2O

      When 1.00 g of ferrochrome is dissolved in dilute sulfuric acid and then titrated, 13.1 cm3 of 0.100 mol dm-3 K2Cr2O7 is needed for the complete reaction.

      In the sample of ferrochrome, what is the percentage by mass of Fe?

      • fraction numerator 13.1 space cross times space 0.1 space cross times space 6 space cross times space 55.85 space cross times space 100 over denominator 1000 space cross times space 1 end fraction

      • fraction numerator 13.1 space cross times space 0.1 space cross times space 6 space cross times space 55.85 over denominator 1000 end fraction

      • fraction numerator 13.1 space cross times space 0.1 space cross times space 55.85 space cross times space 100 over denominator 1000 space cross times space 1 end fraction

      • fraction numerator 13.1 space cross times space 0.1 space cross times space 6 space cross times 55.85 space cross times space 1000 over denominator 100 space cross times space 1 end fraction

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      51 mark

      10 cm3 of methane and 10 cm3 of ethane were sparked with an excess of oxygen. Once cooled, the remaining gas was passed through aqueous potassium hydroxide, which absorbs carbon dioxide.

      Assume all measurements were taken at 25˚C and 1 atm pressure. 

      What volume of gas is absorbed by the alkali?

      • 45 cm3

      • 30 cm3

      • 20 cm3

      • 10 cm3

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      61 mark

      A solution of Sn2+ ions will reduce MnO4- ions to Mn2+ ions when acidified. The Sn2+ ions are oxidised to Sn4+ ions in this reaction.

      How many moles of Mn2+ ions are formed when a solution containing 18.96 g of SnCl2?

      (Mr : 189.60) is added to an excess of acidified KMnO4 solution?

      • 0.010

      • 0.015

      • 0.040

      • 0.050

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      71 mark

      Some fireworks can use the reaction between aluminium powder and anhydrous barium nitrate as a propellant. Metal oxides and nitrogen are the only products when this happens.

      10Al + 3Ba(NO3)2 → 5Al2O3 + 3BaO + 3N2

      When 0.783 g of anhydrous barium nitrate (Mr 261.35) reacts with an excess of aluminium what is the volume of nitrogen produced in cm3?
      (Molar volume of a gas at stp = 22.7 dm3)

      • fraction numerator 0.783 space cross times space 22.7 space cross times space 3 over denominator 261.35 end fraction

      • fraction numerator 261.35 space cross times space 22700 over denominator 0.783 space cross times space 1000 end fraction

      • fraction numerator 261.35 over denominator 0.783 space cross times space 22700 end fraction

      • fraction numerator 0.783 space cross times 22700 over denominator 261.35 end fraction

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      81 mark

      A periodic table is needed for this question

      Excess acidified potassium dichromate(VI) was mixed with 2.76 g of ethanol. The reaction mixture was then boiled under reflux for one hour. Once the reaction had completed, the organic product was collected by distillation.

      The yield of the product was 75.0%

      What is the mass of the product collected?

      • fraction numerator 2.76 space cross times space 60.06 over denominator 46.08 end fraction

      • fraction numerator 75 space cross times space 2.76 space cross times space 60.06 over denominator 100 space cross times space 46.08 end fraction

      • fraction numerator 100 space cross times space 2.76 space cross times space 60.06 over denominator 75 space cross times space 46.08 end fraction

      • fraction numerator 75 space cross times space 2.76 space cross times 46.08 over denominator 100 space cross times space 60.06 end fraction

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      91 mark

      The concentration of calcium ions in a sample of water can be determined by using an ion-exchange column, shown in the diagram below:1-2-h-q9-ib-chemistry-mcqs

       A 50 cm3 sample of water containing dissolved calcium sulfate was passed through the ion-exchange resin.

      Each calcium ion in the sample was exchanged for two hydrogen ions. The resulting acidic solution collected in the flask required 25 cm3 of 1.0 x 10-2 mol dm-3 potassium hydroxide for complete neutralisation.

      What was the concentration of the calcium sulfate in the original sample?

      • fraction numerator 0.050 space cross times space 1.0 space cross times space 10 to the power of negative 2 end exponent over denominator bold 2 bold space bold cross times bold space bold 0 bold. bold 025 end fraction

      • fraction numerator 0.025 space cross times space 1.0 space cross times space 10 to the power of negative 2 end exponent over denominator bold 0 bold. bold 050 end fraction

      • fraction numerator 25 space cross times space 1.0 space cross times space 10 to the power of negative 2 end exponent over denominator bold 2 bold space bold cross times bold space bold 0 bold. bold 050 end fraction

      • fraction numerator 0.025 space cross times space 1.0 space cross times space 10 to the power of negative 2 end exponent over denominator bold 2 bold space bold cross times bold space bold 0 bold. bold 050 end fraction

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      101 mark

      A tube of volume 0.3 dm3 is filled with a gas at 27oC and 100kPa, the mass of the tube increases by 1.01×10-3 kg.

      Assume the gas is obeying the ideal gas laws.

      If Mr is the Molar mass of the gas, what is the mass of this sample of gas?

      • fraction numerator 100000 space cross times space 0.0003 over denominator 8.314 space cross times space 27 space cross times space straight M subscript straight r end fraction

      • fraction numerator 100 space cross times space 0.0003 space cross times space straight M subscript straight r over denominator 8.314 space cross times space 300 end fraction

      • fraction numerator 100000 space cross times space 0.3 space cross times space straight M subscript straight r over denominator 8.314 space cross times space 300 end fraction

      • fraction numerator 100000 space cross times space 0.0003 space cross times space straight M subscript straight r over denominator 8.314 space cross times space 300 end fraction

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      111 mark

      The glass containers X and Y are connected by a closed valve.1-2-h-q11-ib-chemistry-mcqs

      X contains pure CO2 gas at 25 °C and a pressure of 1 × 105 Pa. Container Y has been evacuated prior to the experiment and has a volume three times bigger than container X.

      During the experiment, the valve is opened, and the temperature of the whole apparatus is raised to 160 °C.

      What is the final pressure in the system?

      • fraction numerator 1 space cross times space 10 to the power of 5 space cross times space 160 over denominator 4 space cross times space 25 end fraction

      • fraction numerator 4 space cross times space 10 to the power of 5 space cross times space 433 over denominator 3 space cross times space 298 end fraction

      • fraction numerator 1 space cross times space 10 to the power of 5 space cross times space 433 over denominator 3 space cross times space 298 end fraction

      • fraction numerator 1 space cross times space 10 to the power of 5 space cross times space 433 over denominator 4 space cross times space 298 end fraction

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      121 mark

      Iodine is a shiny, black solid. Solid iodine sublimes easily when heated to produce a purple vapour.

      A block of solid iodine is put into a closed container and completely sublimed to produce 1.3 dm3 of iodine vapour. It is then kept at a constant temperature and pressure of 100kPa. 

      The empty container had a mass of 3.22 g and when iodine was added the mass increased to 9.57 g. (Mr I2= 253.8) 

      If iodine vapour acts as an ideal gas, what is the approximate temperature of the iodine vapour?

      • fraction numerator open parentheses 9.57 space minus space 3.22 close parentheses space cross times space 100000 space cross times space 0.0013 over denominator 253.8 space cross times space 8.314 end fraction

      • fraction numerator 253.8 space cross times space 100000 space cross times space 0.0013 over denominator open parentheses 9.57 space minus space 3.22 close parentheses space cross times space 8.314 end fraction

      • fraction numerator 253.8 space cross times space 100000 space cross times space 1.3 over denominator open parentheses 9.57 space minus space 3.22 close parentheses space cross times space 8.314 end fraction

      • fraction numerator 253.8 space cross times space 100 space cross times space 0.0013 over denominator open parentheses 9.57 space minus space 3.22 close parentheses space cross times space 8.314 end fraction

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