This question is about gas volumes.
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Give your answer in cm3 and dm3.
What are the temperature and pressure implied with room temperature and pressure?
State one equation to calculate the amount of gas in moles.
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This question is about gas volumes.
Â
Give your answer in cm3 and dm3.
What are the temperature and pressure implied with room temperature and pressure?
State one equation to calculate the amount of gas in moles.
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Ethanol, C2H5OH, undergoes complete combustion to form carbon dioxide and water.
Complete the balanced symbol equation for the complete combustion of ethanol.
 ___ C2H5OH + ___ O2 → ___ CO2 + ___ H2O
Which of the chemicals in the reaction equation are gases at room temperature and pressure?Â
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Draw a circle around the correct word to complete the sentences.
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9 moles of oxygen produce |
|
of carbon dioxide. |
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A volume of |
|
of carbon dioxide is released. |
Â
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0.0625 moles of methane is burnt in air according to the following equation:
CH4 + 2O2 → CO2 + 2H2O
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Tick (✓) one box.Â
0.03125 | Â |
0.0625 | Â |
0.125 | Â |
If the reaction is completed at room temperature and pressure, what volume, in dm3, of methane is being burned?
If the reaction was completed at room temperature and pressure, what volume, in dm3, of carbon dioxide is produced?
Assuming that all the chemicals involved in the reaction are in the gaseous state, the balanced symbol equation is:
CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (g)
Draw a circle around the correct answer to complete the sentence.
Burning 2500 cm3 of methane produces a total volume of |
|
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Helium is a gas at room temperature and pressure.
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Relative atomic mass (Ar):Â Â Â He = 4
Use the equation:Â
What volume of gas, in cm3 and dm3, does 38.4 g of helium occupy?
Chlorine, Cl2, is a gas at room temperature and pressure.
Calculate the number of moles in a 376.3 g sample of chlorine.Â
Relative atomic mass (Ar):Â Â Â Cl= 35.5Â
Use the equation:Â
What volume of gas, in cm3 and dm3, does 376.3 g of chlorine occupy?
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Carbon dioxide and water are formed when propane undergoes complete combustion.
The equation for the reaction is:
C3H8 (g) + 5 O2 (g) → 3 CO2 (g) + 4 H2O (l)
Calculate the number of moles in 55.44 g of propane.
 Relative molecular mass (Mr):   C3H8 = 44
What volume of gas, in dm3, does 55.44 g of propane occupy?
What volume of carbon dioxide is produced when 55.44 g undergoes complete combustion?
In another combustion experiment, 1.3 dm3 of propane is combusted in the presence of 8.0 dm3 of oxygen.
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Give your answer in cm3.
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Nitrogen and hydrogen react together in the Haber process to produce ammonia.
Figure 1 shows a flow diagram for the process
Figure 1
A gaseous mixture of NH3, N2 and H2 leaves the reactor where the ammonia is separated and the hydrogen and nitrogen are recycled back into the reactor. The reactor has a temperature of 450 oC and a pressure of 200 atmospheres.
What does Avogadro's Law state about all three gases?
The gases have the following boiling points:
Gas | Boiling Point (oC) |
Ammonia | -33 |
Nitrogen | -196 |
Hydrogen | -253 |
Suggest how ammonia can be separated from the other gases.Â
The equation for the Haber process is:
N2 (g)  +  3H2 (g)  ⇌  2NH3 (g)
Calculate the volume of ammonia produced from the complete reaction of 795 dm 3 of hydrogen.
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A student investigated the electrolysis of a solution of sodium chloride by measuring how the volume of gases produced changes with time.
Figure 1 shows the apparatus used in the investigation.
Figure 1
The student made an error in designing and setting up the apparatus for this investigation.
Identify the error and suggest what needs to be changed.
The student soon adjusted the apparatus and was able to perform the investigation correctly.Â
The student measured the volumes of gases produced every minute for 20 minutes and constructed a graph of these results.
Figure 2 shows the graph of the investigation.
Figure 2
Using the graph, describe the trends shown in the results.
The number of moles of each gas produced at each electrode is the same and no gas escapes from the apparatus however there is a difference in the amount of gas collected.
Suggest one reason for the difference in volume of each gas collected.
Using Figure 2, calculate the amount in moles of chlorine collected after 16 minutes.
The volume of one mole of any gas at room temperature and pressure is 24.0 dm3
State your answer in standard form.
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What is the volume occupied by 5.6 g of nitrogen gas at RTP?
Relative atomic masses (Ar): N= 14
2.4 dm3
4.8 dm3
9.6 dm3
12 dm3
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This question is about calculating the volumes of gases produced in different reactions.
What volume of hydrogen is produced from the reaction of 2.5 g of magnesium with excess sulfuric acid?
Mg  +  H2SO4 →  MgSO4 +  H2Â
Relative atomic mass (Ar): Mg = 24
What volume of steam is produced from the combustion of 2.000 kg of methane in excess oxygen?
CH4  +  2O2   →  CO2   +   2H2OÂ
Relative formula mass (Mr): CH4 = 16
What mass of iodine is required to react with hydrogen to produce 67.20 dm3 of hydrogen iodide?
I2  +  H2   →  2 HI
Relative atomic mass (Ar): I = 127
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The reaction between nitrogen and hydrogen produces ammonia.
N2 (g) + 3H2 (g)Â Â 2NH3 (g)
What volume of ammonia is produced from 565 cm3 of hydrogen?
1130 cm3
377 cm3
283 cm3
847 cm3
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A gas cylinder has a volume of 264 dm3. Â
What mass of hydrogen does it contain?
Relative atomic masses (Ar): H=1
22 g
11 g
24 g
264 g
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Air bags are designed to protect car passengers in the event of an accident.Â
Crash sensors in the car detect an impact and immediately heat a small container with a mixture of chemicals.Â
The heat produced triggers a chemical reaction which produces nitrogen gas.Â
The gas fills the bag which provides the cushion needed for protection.
Figure 1 demonstrates this process.
The chemical mix contains sodium azide (NaN3) which undergoes thermal decomposition to form sodium and nitrogen.
The equation for the reaction is:
2NaN3       →      2Na       +      3N2
A typical air bag contains around 143 g of sodium azide.
Calculate the mass of nitrogen produced when 143 g of sodium azide decomposes.
Relative atomic masses (Ar): N = 14; Na = 23
1 g of nitrogen has a volume of 0.86 litres at room temperature and pressure.
What volume of nitrogen would be produced from 143 g of sodium azide?
(If you did not answer part (a), assume that the mass of nitrogen produced from 143 g of sodium azide is 85 g. This is not the correct answer to part a))
State the conditions of temperature and pressure at r.t.p.
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This question is about electrolysis.
In the electrolysis of molten potassium bromide, separate reactions occur at the electrodes.
Write two balanced half equations for the reactions that occur at the anode and the cathode.
During the electrolysis of molten potassium bromide, 3.12 g of potassium was formed.Â
Calculate the number of moles of bromine formed in the reaction.Â
Relative atomic masses (Ar):   K = 39,   Br = 80
11.3% of the bromine produced in the reaction escapes the container.Â
Calculate the volume, in dm3, of bromine in the container.
When molten sodium chloride was electrolysed, 0.28 g of sodium was formed at one electrode.Â
Calculate the volume of gas, in cm3, that was produced at room temperature and pressure.Â
Relative atomic masses (Ar):   Na = 23,   Cl = 35.5
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This question is about combustion.
A 0.050 mol sample of a hydrocarbon was burned in excess oxygen.
To determine the identity of the hydrocarbon, the type of combustion used is important.
Which type of combustion should be used to determine the identity of the hydrocarbon? Explain your reasoning.
3.6 dm3 of carbon dioxide were produced during the complete combustion of the 0.050 mol sample of a hydrocarbon.
Calculate the number of moles of carbon dioxide released.
When the hydrocarbon was burned 1.204 x 1023 molecules of water were produced.Â
Calculate the number of moles of hydrogen atoms in 1.204 x 1023 molecules of water.
The amount of hydrocarbon burned was 0.050 mol.
Calculate the molecular formula of the hydrocarbon.
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Sodium carbonate reacts with dilute hydrochloric acid:
Na2CO3 + 2HCl → 2NaCl + H2O + CO2
A student investigated the volume of carbon dioxide produced when different masses of sodium carbonate were reacted with dilute hydrochloric acid.
This is the method used.
The student has set the apparatus incorrectly as shown in Figure 1.
Figure 1
Identify the error and describe what would happen if the student used the apparatus.
The student corrected the error and collected the results shown in Table 1.
Table 1
Mass of sodium carbonate in g | 0.07 | 0.12 | 0.23 | 0.29 | 0.34 | 0.54 | 0.59 | 0.65 |
Volume of carbon dioxide gas in cm3 | 16.0 | 27.5 | 52.0 | 65.0 | 77.0 | 95.0 | 95.0 | 95.0 |
Suggest why the volume of carbon dioxide collected reaches a maximum of 95.0 cm3.
Describe how the student could accurately determine the minimum mass of sodium carbonate required to produce 95.0 cm3 of carbon dioxide.
The carbon dioxide was collected at room temperature and pressure.Â
Calculate the number of atoms of oxygen present in the 95.0 cm3 of carbon dioxide produced.Â
Give your answer to three significant figures.
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Air bags contain sodium azide (NaN3) which decomposes on heating to form sodium and nitrogen.
2NaN3    →    2Na    +    3N2
What volume of nitrogen would be produced from 13 g of sodium azide?
Relative atomic mass (Ar): N = 14
Relative formula mass (Mr): NaN3 = 65
4.8 dm3
7.2 dm3
48 dm3
72 dm3
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This question is about power stations.
Coal-fired power stations are being phased out as the supply of coal decreases and greater restrictions on emissions are implemented.
Coal typically contains between 0.2% and 5% sulfur by dry weight.
Calculate the average number of moles of sulfur in 75 tonnes of coal.Â
Relative atomic mass (Ar):Â Â Â S = 32
1 tonne = 1 x 106 g
Calculate the volume of sulfur dioxide released from the combustion of 75 tonnes of typical coal.
Natural gas is replacing coal in some power stations.Â
The typical sulphur content of natural gas is 5.5 x 10–6 g / dm3.Â
An articulated fuel tanker truck can carry up to 36000 dm3 of natural gas.Â
Calculate the volume, in cm3, of sulfur dioxide that could be released by combusting the 36000 dm3 of natural gas carried in the tanker truck.
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Hydrogen can be produced by reacting methane with steam:Â
CH4 + H2O  → CO + 3H2
What volume would the products occupy at RTP after reacting 32 g of methane with excess steam? Â
Relative atomic masses (Ar):Â C = 12Â Â H = 1Â Â O = 16
24 dm3
72 dm3
96 dm3
192 dm3
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This question is about the reduction of tungsten oxide, WO3.
A teacher reduces tungsten oxide to tungsten using the following method and the equipment shown in Figure 1.
Figure 1
Write the balanced symbol equation, including state symbols, for the reduction of tungsten oxide by hydrogen.
State one addition to the method to check that the tungsten oxide has been completely reduced.
In industry, tungsten oxide is reduced on a large scale using hydrogen.
Using your equation from part (a), calculate the minimum volume, in dm3, of hydrogen that is required to react with 13.92 tonnes of tungsten oxide.Â
Relative atomic masses (Ar):   W = 184,   O = 16,   H = 1Â
1 tonne = 1 x 106 g
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