Environmental and Atmospheric Chemistry — Free IB MYP5 Chemistry Questions

1QuestionCarbon dioxide and its role in natural cyclesConcept Practice

2 marks~3 minCriterion A

A student exhales through a straw into a flask containing a clear, colourless solution of limewater (

Ca(OH)_2

). After two minutes, the solution turns cloudy.

a

Identify the gas being tested for in this experiment. [1]

b

The cloudiness results from a precipitation reaction. Write the balanced chemical equation for this reaction, and deduce what the cloudy precipitate tells you about the composition of exhaled air compared to inhaled air. [1]

Solutions

2QuestionComplete vs incomplete combustionConcept Practice

2 marks~3 minCriterion B

Four trials of burning methane (

\text{CH}_4

) are conducted, each using 5.0 g of fuel. The oxygen-to-fuel ratio is varied across trials.

Trial	1	2	3	4
Oxygen-to-fuel ratio	1.5:1	2.0:1	2.5:1	3.0:1
Flame colour	yellow	orange-yellow	blue-yellow	blue
Soot produced	heavy	moderate	slight	none

a

Deduce the relationship between oxygen-to-fuel ratio and soot production shown by these results. [1]

b

Identify the controlled variable and the manipulated variable in this experiment. [1]

Solutions

3QuestionComplete vs incomplete combustionConcept Practice

2 marks~3 minCriterion A

A Bunsen burner produces a blue flame when the air hole is fully open and a yellow flame when the air hole is partially closed. Soot deposits are visible near the yellow flame.

a

Identify the black substance deposited as soot. [1]

b

Explain why soot forms when the air hole is partially closed rather than fully open. [1]

Solutions

4QuestionGlobal warming vs climate changeConcept Practice

2 marks~3 minCriterion A

The diagram shows a simplified model of Earth's atmosphere. Incoming solar radiation passes through the atmosphere and warms Earth's surface. The surface then emits infrared radiation, some of which is absorbed by molecule X shown in the diagram.

a

Identify molecule X. [1]

b

Explain how molecule X contributes to the greenhouse effect. [1]

Solutions

5QuestionpH scale and acidity measurementConcept Practice

2 marks~3 minCriterion A

Three strips of universal indicator paper were each dipped into a different substance.

- Strip A was dipped in lemon juice and turned red.
- Strip B was dipped in pure water and turned green.
- Strip C was dipped in soap solution and turned purple.

a

Deduce the nature (acidic, neutral, or alkaline) of each substance, based on the colour changes observed. [1]

b

Acid rain has a pH of approximately 4. Explain why acid rain, despite being acidic, causes less damage to living organisms than the substance in Strip A would if consumed in large quantities. [1]

Solutions

6QuestionStructure and function of the ozone layerConcept Practice

2 marks~3 minCriterion A

The diagram shows the four main layers of Earth's atmosphere: troposphere, stratosphere, mesosphere, and thermosphere.

a

Identify the atmospheric layer in which the ozone layer is found. [1]

b

Ozone absorbs harmful ultraviolet (UV) radiation from the Sun. Explain why the absence of ozone in this layer would be damaging to life on Earth's surface. [1]

Solutions

7QuestionConcept of sustainability and resource managementConcept Practice

2 marks~3 minCriterion A

A recycling facility uses a conveyor belt to carry mixed waste past two separators: a magnetic separator and an eddy current separator. The magnetic separator contains a powerful electromagnet. The eddy current separator spins a rapidly rotating drum of alternating magnetic poles, inducing currents in nearby metals.

a

Identify which separator is used to remove ferrous metals such as iron and steel from the mixed waste. [1]

b

Explain why the eddy current separator cannot be used to separate ferrous metals in the same way it separates non-ferrous metals such as aluminium. [1]

Solutions

8QuestionTypes of recyclable materials (plastics, metals, glass)Concept Practice

4 marks~6 minCriterion A

Three common household items are shown: a plastic bottle made from PET (polyethylene terephthalate), an aluminium can, and a glass jar.

a

State the full chemical name of the material used to make the plastic bottle. [1]

b

For two of the three items, identify the material and state one property that makes each material recyclable. [2]

c

Explain why aluminium is considered more economically valuable to recycle than glass, despite both being infinitely recyclable. [1]

Solutions

9QuestionDesalination techniques (distillation, reverse osmosis)Concept Practice

2 marks~3 minCriterion A

The diagram below shows a laboratory distillation apparatus used to desalinate seawater. Component X is labelled on the diagram.

a

Identify component X. [1]

b

Explain how component X enables pure water to be collected during desalination. [1]

Solutions

10QuestionRole of oxygen in respiration and combustionAssessment Practice

3 marks~5 minCriterion B

When 10 g samples of three fuels are completely burned in excess oxygen, the following data are recorded.

Fuel — Carbon atoms per molecule — Mass of

CO_2

produced (g)

Ethanol ( $C_2H_5OH$ )	2	19.1
Propane ( $C_3H_8$ )	3	30.0
Butane ( $C_4H_{10}$ )	4	30.4

a

Calculate the mass of

CO_2

produced per gram of fuel for each of the three fuels. [1]

b

Identify the trend in your calculated values as the number of carbon atoms per molecule increases. [1]

c

Explain why fuels with a greater number of carbon atoms per molecule produce more

CO_2

per gram of fuel during complete combustion. [1]

Solutions

11QuestionLayers of the atmosphere (troposphere, stratosphere, etc.)Assessment Practice

2 marks~3 minCriterion D

Chlorofluorocarbons (CFCs) released at ground level slowly migrate to the stratosphere, where UV radiation breaks them down, releasing chlorine radicals that catalytically destroy ozone molecules.

a

Explain one impact of stratospheric ozone depletion on human health. [1]

b

Identify one limitation of using laboratory data to predict the rate of ozone depletion in the real atmosphere. [1]

Solutions

12QuestionCarbon dioxide and its role in natural cyclesAssessment Practice

6 marks~9 minCriterion C

The table below shows the solubility of carbon dioxide (

\text{CO}_2

) in water at constant pressure (1 atm).

Temperature (°C)	0	10	20	30	40
Solubility (g $\text{CO}_2$ per 100 g $\text{H}_2\text{O}$ )	0.335	0.257	0.198	0.155	0.125

a

Describe the trend in solubility of

\text{CO}_2

as temperature increases from 0°C to 40°C, including reference to specific values. [2]

b

Explain, using intermolecular forces and energy, why increasing temperature produces this trend. [2]

c

A scientist claims that warming ocean surface water from 20°C to 40°C will release significantly more

\text{CO}_2

into the atmosphere than warming it from 0°C to 20°C. Evaluate this claim using the data provided. [2]

Solutions

13QuestionComplete vs incomplete combustionAssessment Practice

8 marks~12 minCriterion D

A city council is considering replacing its diesel bus fleet with compressed natural gas (CNG) buses. The following data are available.

Diesel: energy content

36.4 \ \text{MJ/L}

; CO

_2

emission factor

2.68 \ \text{kg CO}_2\text{/L}

; particulate matter (PM) emission factor

0.12 \ \text{g PM/km}

; fuel consumption

0.40 \ \text{L/km}

.

CNG: energy content

38.2 \ \text{MJ/m}^3

; CO

_2

emission factor

2.75 \ \text{kg CO}_2\text{/m}^3

; PM emission factor

0.005 \ \text{g PM/km}

; fuel consumption

0.35 \ \text{m}^3\text{/km}

.

a

Calculate the CO

_2

emissions per kilometre for each fuel type. [2]

b

Using your results from (a) and the PM data, deduce which fuel type produces more energy per unit of CO

_2

emitted, and explain what this reveals about the relative carbon intensity of each fuel. [2]

c

Evaluate whether the council should switch to CNG buses, considering both the societal benefit from reduced PM emissions and the environmental impact of CO

_2

emissions. In your evaluation, identify and discuss two limitations of the data model provided. [4]

Solutions

14QuestionFormation of carbon monoxide and sootAssessment Practice

6 marks~9 minCriterion C

A family installs a gas heater that burns methane (

CH_4

). A blocked air vent restricts the oxygen supply, causing incomplete combustion and producing carbon monoxide (

CO

) rather than carbon dioxide (

CO_2

).

a

Explain why a restricted oxygen supply leads to the formation of

CO

instead of

CO_2

during combustion. Include the balanced chemical equation for the incomplete combustion of methane producing

CO

and water (

H_2O

). [2]

b

Explain how inhaled carbon monoxide affects the ability of blood to transport oxygen to body tissues. [2]

c

The family installs a single

CO

detector in the basement. Analyse the limitations of this safety arrangement for a multi-storey house and justify a specific improvement to their safety plan. [2]

Solutions

15QuestionGreenhouse effect mechanismAssessment Practice

2 marks~3 minCriterion B

The table below shows atmospheric CO

_2

concentration and average global temperature recorded over four decades.

Decade	1970	1980	1990	2000
CO $_2$ concentration (ppm)	325	338	354	369
Average global temperature (°C)	14.0	14.2	14.4	14.6

a

Deduce the relationship between CO

_2

concentration and average global temperature using data from the table. [1]

b

The CO

_2

concentration is projected to reach 400 ppm. Calculate the estimated average global temperature at this concentration, showing your reasoning clearly. [1]

Solutions

16QuestionCarbon footprint and reduction strategiesAssessment Practice

2 marks~3 minCriterion D

A household consumes 5000 kWh of electricity annually. The national grid emission factor is 0.5 kg CO2 per kWh.

a

Calculate the household's annual CO2 emissions in tonnes. [1]

b

The emission factor is assumed to be constant throughout the year. Explain how this assumption could affect the accuracy of the calculated carbon footprint. [1]

Solutions

17QuestionGreenhouse effect mechanismAssessment Practice

4 marks~6 minCriterion C

Infrared absorption data for three greenhouse gases are given below.

CO_2

absorbs at: 2.0–2.8, 4.2–4.4, 13–17

\mu m

CH_4

absorbs at: 3.2–3.5, 7.0–8.3

\mu m

H_2O

absorbs at: 5.5–7.5, 12–20, 20–100

\mu m

A fourth atmospheric gas, X, shows a strong absorption peak at 8–12

\mu m

and a weaker peak near 4.5

\mu m

. The 8–12

\mu m

region is the atmospheric window, where

CO_2

,

CH_4

, and

H_2O

absorb very little infrared radiation.

a

Deduce the identity of gas X from the following options:

N_2O

,

O_2

,

Ar

, or

CFC\text{-}12

(

CCl_2F_2

). Justify your reasoning by comparing the absorption data of gas X with that of the three gases above. [2]

b

Discuss why an equal concentration of gas X in the atmosphere produces a greater enhancement of the greenhouse effect than

CO_2

. [2]

Solutions

18QuestionChemical equations leading to acidic precipitationAssessment Practice

8 marks~12 minCriterion B

When nonmetal oxides dissolve in water, they form acidic solutions. The table below shows data for four oxides relevant to acid rain.

Oxide	$CO_2$	$SO_2$	$NO_2$	$SO_3$
pH of solution	5.6	4.5	3.2	2.1
Oxidation state of nonmetal	+4	+4	+4	+6

a

Describe the trend in pH as the oxidation state of the nonmetal increases, using data from the table to support your answer. [2]

b

Deduce the pH of the solution formed when

P_4O_{10}

reacts with water, given that phosphorus has an oxidation state of +5 in this oxide. Use the trend from part (a) to support your reasoning. [2]

c

Justify why nonmetal oxides with higher oxidation states produce more acidic solutions, by explaining how the oxidation state affects O–H bond polarity in the oxyacid formed and how this determines the strength of the acid. [4]

Solutions

19QuestionEffects on soil, water bodies, and buildingsAssessment Practice

2 marks~3 minCriterion D

Acid rain containing sulfuric acid reacts with limestone (calcium carbonate) in buildings, causing structural damage.

a

Complete and balance the chemical equation for this reaction:

CaCO_3(s) + H_2SO_4(aq) \rightarrow

Explain how the products cause damage to the limestone structure. [1]

b

Granite is sometimes proposed as a replacement for limestone in heritage building restoration. Explain why granite resists acid rain more effectively than limestone, and discuss whether replacing limestone with granite fully eliminates the risk of weathering damage. [1]

Solutions

20QuestionMethods to reduce acid rain (clean fuels, scrubbers)Assessment Practice

6 marks~9 minCriterion C

A wet scrubber removes

SO_2

from industrial flue gas using a

CaCO_3

slurry:

CaCO_3(s) + SO_2(g) \rightarrow CaSO_3(s) + CO_2(g)

SO_2

removal efficiency was measured at two pH levels across a range of inlet gas temperatures.

Inlet gas temperature (°C)	25	35	45	55	65
$SO_2$ removal at pH 5.0 (\%)	92	88	82	75	68
$SO_2$ removal at pH 6.0 (\%)	95	91	70	78	72

a

Describe the trend in

SO_2

removal efficiency as temperature increases at pH 5.0. [1]

b

Identify the anomalous data point at pH 6.0, stating the temperature at which it occurs and how it departs from the expected trend. [2]

c

Analyse why

SO_2

removal efficiency at pH 6.0 is generally higher than at pH 5.0, and explain why the anomaly at 45°C is more pronounced at pH 6.0 than at pH 5.0. [3]

Solutions

21QuestionInternational agreements (e.g., Montreal Protocol)Assessment Practice

2 marks~3 minCriterion B

The ozone depletion potential (ODP) values for several compounds are given below.

Compound	CFC-11	CFC-12	HCFC-22	HCFC-123	HFC-134a
ODP	1.0	0.82	0.05	0.02	0.0

a

Deduce the trend in ODP values as the molecular structure transitions from CFCs to HCFCs to HFCs, and identify the structural feature responsible for this trend. [1]

b

A new refrigerant, HFC-152a, contains no chlorine atoms and has a molecular structure similar to HFC-134a. Deduce its ODP value and justify your answer using the trend identified in part (a). [1]

Solutions

22QuestionInternational agreements (e.g., Montreal Protocol)Assessment Practice

5 marks~8 minCriterion D

In Antarctica during the 1980s, researchers measured UV-B intensity at ground level under identical solar angles and cloud cover. On Day 1 (intact ozone layer), UV-B intensity was 12 W/m². On Day 2 (depleted ozone layer), UV-B intensity was 20 W/m². Atmospheric CFC-11 concentration rose from 170 ppt in 1980 to 270 ppt in 1990.

A hypothesis states: "CFCs cause ozone depletion, which leads to increased UV-B radiation at ground level."

a

Calculate the percentage increase in UV-B intensity from Day 1 to Day 2. [1]

b

Calculate the percentage increase in CFC-11 concentration from 1980 to 1990. [1]

c

Using both calculated values, evaluate whether the data support the hypothesis. In your answer, compare the two percentage changes and discuss one limitation of drawing a conclusion from this evidence. [3]

Solutions

23QuestionStructure and function of the ozone layerAssessment Practice

5 marks~8 minCriterion C

In the 1980s, Antarctic field experiments measured ozone and CFC-11 concentrations at various altitudes. Results are shown below.

Altitude (km)	10	15	20	25	30
Ozone concentration (ppb)	0.2	0.5	1.5	3.0	2.5
CFC-11 concentration (ppt)	150	120	80	40	20

The hypothesis is that CFCs catalytically destroy ozone via the chlorine radical cycle:

\text{Cl} + \text{O}_3 \rightarrow \text{ClO} + \text{O}_2

\text{ClO} + \text{O} \rightarrow \text{Cl} + \text{O}_2

a

Describe the trend in each concentration with increasing altitude. [2]

b

Explain how the chlorine radical cycle predicts a relationship between CFC-11 concentration and ozone concentration. [1]

c

Evaluate whether the data supports the hypothesis, identifying at least one limitation of the evidence. [2]

Solutions

24QuestionEnvironmental impact of waste and landfillAssessment Practice

2 marks~3 minCriterion D

A local council treats landfill leachate containing dissolved

Pb^{2+}

and

Cu^{2+}

ions by adding lime (

Ca(OH)_2

), which causes the heavy metals to precipitate as insoluble hydroxides such as

Pb(OH)_2

and

Cu(OH)_2

.

a

Identify one industry or sector, other than landfill management, where chemical precipitation with lime is used to remove heavy metal ions from wastewater. [1]

b

Explain one limitation of using lime precipitation as the sole treatment method for landfill leachate. [1]

Solutions

25QuestionReduce, Reuse, Recycle (3Rs) strategiesAssessment Practice

5 marks~8 minCriterion C

The diagram shows simplified molecular structures of two polymers: polyethene and poly(lactic acid) (PLA).

Polyethene consists of long hydrocarbon chains with only

\text{C-C}

and

\text{C-H}

bonds. PLA contains repeating ester linkages (

\text{-COO-}

) in its backbone, derived from lactic acid monomers.

a

Explain why polyethene is resistant to breakdown by microorganisms in landfill. [2]

b

Explain why PLA is broken down more readily than polyethene by microorganisms. [2]

c

A landfill operator claims that increasing temperature and moisture content will significantly accelerate PLA degradation, but will have negligible effect on polyethene degradation. Evaluate this claim. [1]

Solutions

26QuestionRole of chlorine and disinfection methodsAssessment Practice

2 marks~3 minCriterion B

A water treatment plant disinfects drinking water by adding chlorine to eliminate E. coli. The data below show the contact time required to kill 99.9% of E. coli at 20°C.

Chlorine dose (mg/L)	0.5	1.0	1.5	2.0
Contact time (min)	12	6	4	3

a

Deduce the mathematical relationship between chlorine dose and contact time, showing clearly how the data support your answer. [1]

b

A treatment plant operates at a chlorine dose of 2.5 mg/L but must achieve 99.9% kill of E. coli within 2 minutes. Evaluate whether this dose is sufficient, using your relationship from (a). [1]

Solutions

27QuestionRole of chlorine and disinfection methodsAssessment Practice

3 marks~5 minCriterion C

A water treatment plant adds chlorine at an initial dose of 2.0 mg/L to a reservoir sample. The graph below shows how free chlorine concentration changes over 60 minutes.

a

Identify the two distinct phases visible in the chlorine decay curve. [1]

b

Explain the chemical reactions responsible for the initial rapid decrease in chlorine concentration. [1]

c

Explain why the rate of chlorine decay slows during the second phase, and evaluate what this implies about the effectiveness of disinfection over time. [1]

Solutions

28QuestionDesalination techniques (distillation, reverse osmosis)Assessment Practice

6 marks~9 minCriterion D

A coastal city facing severe drought is considering a large-scale reverse osmosis (RO) desalination plant powered by a fossil fuel station. Seawater is forced through semi-permeable membranes under high pressure, producing fresh water and a concentrated brine waste discharged directly into the ocean.

a

State one societal benefit of building this plant and explain how it directly addresses the city's water crisis. [2]

b

Identify two distinct environmental costs associated with operating this plant, one linked to brine discharge and one linked to energy source. [2]

c

Evaluate two limitations of using a cost–benefit model to assess this plant's overall impact, referring to assumptions made or gaps in available data. [2]

Solutions

Environmental and Atmospheric Chemistry — Free MYP5 Chemistry Practice Questions