Table of Contents
BEST IELTS Academic Reading Test 236
IELTS ACADEMIC READING TEST-PASSAGE – 2
IELTS ACADEMIC READING TEST
READING PASSAGE – 2
Hydrogen + Oxygen
Why can’t we just manufacture water?
The availability of water in the developed world is becoming a matter of concern, but for less developed nations, this has been a problem for a long time. For hundreds of years many populations have not had access to clean drinking water, and the poor have suffered particularly. Water may be available in some areas, but it is often ridden with pathogens and can be fatal to drink. In other places, there is no water supply at all. About a fifth of the world’s people do not have access to clean drinking water. Would it be possible to solve this problem by creating water?
The chemical make-up of water is two hydrogen atoms that are attached to one oxygen atom. This is seemingly basic chemistry, so why don’t we just join them up and solve all the world’s water problems? Well, it is easier said than done. In theory it is doable, but it is extremely unsafe. We have to have both oxygen and hydrogen atoms to make water. Just mixing them together does not mean they combine chemically. To make H₂O, the electrons of both have to link up, and we need the addition of intense heat and force to get them to do this.
BEST IELTS Academic Reading Test 236
With oxygen supporting combustion and hydrogen being extremely flammable, this would be easy to create. All that is needed is a spark, not even a flame, and kaboom – we have water! The oxygen and hydrogen atoms will have combined. But we also have to contend with a massive explosion. Consider the Hindenburg, the ill-fated German passenger airship that exploded over New Jersey in 1937. It was kept afloat with hydrogen and as it was landing after a trans-Atlantic flight, static electricity sparked the hydrogen. Mixing with oxygen in the air, the hydrogen exploded and the Hindenburg was enveloped in a ball of fire, completely destroying the ship in about 30 seconds. (Amazingly, 62 of the 97 people on board survived, though most were severely burned.) As a result though, the explosion created a lot of water.
BEST IELTS Academic Reading Test 236
So if we were to produce water in the amounts required to stop water shortages, there would have to be stringent measures to limit the dangers. Then again, the use of nuclear power has even greater risks, with Chernobyl in 1986 and Fukushima in 2011 as horrifying examples, yet nations continue to take the nuclear option. As water becomes scarcer, the benefits of creating it might be seen to outweigh the risks.
Another possible way of obtaining water is from seawater. The desalination process can be done in a number\ of ways. The most traditional is distillation, wherein the salt water is heated with electricity or solar power, and the steam drawn off returns to a liquid state without salt when it cools. The electric powered version is expensive and the solar method is not very efficient at creating large amounts of water as yet.
BEST IELTS Academic Reading Test 236
Reverse osmosis is when salt water is pushed through a water-permeable m embrane that filters the salt. All of Dubai’s drinking water is obtained using this process. This too uses a great deal of energy, though there has been some research using very thin graphene as a membrane, which would reduce the amount of pressure required. Desalination can also be done with electro-dialysis, which removes salts from water with an electric charge also using a membrane. But it does not necessarily provide clean water as the electric\ current does not remove bacteria and solid particles.
Due to their expense, the countries that are currently using these methods tend to be wealthy, so the places that require the technology the most, cannot afford it. There is some question about pollution caused, not only by the methods used to heat or pressurize the water, but also the salt residue that is a by-product. If not returned to the sea very carefully, it can be harmful to marine life, and left on land it is at risk of entering the water table. Solar distillation of seawater looks to be the most sustainable method and research is underway to make it function on a larger scale for drinking water and agriculture. However, many areas that lack water are a long way from the sea, so any of these methods would not be feasible even if better technology or more funds were available.
BEST IELTS Academic Reading Test 236
Another promising method is to extract the water vapour that is always present in the air (to varying degrees depending on the humidity). This vapour is part of the natural cycle that lifts water from the surface of bodies of water such as oceans and lakes, forms clouds and eventually becomes rain. Areas that do not receive this rain would benefit from the water being removed from the cycle at an earlier stage, before it forms into clouds that drop their rain somewhere else. A number of inventions have been proposed that range from windmills to farm vehicles, but much like the desalination processes, they too have had problems with costs, pollution, sustainability and effectiveness. Mostly they have been produced by small-scale inventors and have not had the backing of academia and industry. It is yet to be seen what someone might come up with in the future if research is expanded.
All these methods may have their drawbacks, but they are certainly a step in the right direction. If we continue the search for ways of taking water vapour out of the atmosphere, or came up with improvements in solar distillation, surely a cheaper, cleaner alternative could be arrived at before long?
BEST IELTS Academic Reading Test 236
Questions 14-17
Choose NO MORE THAN THREE WORDS from the passage for each answer.
14. What do many water supplies contain that kill people if they drink from them?
15. What proportion of the world’s people do not have sanitary water to drink?
16. What parts of oxygen and hydrogen atoms need to join to create water?
17. What is the problematic side-effect of creating water from hydrogen and oxygen?
BEST IELTS Academic Reading Test 236
Questions 18-21
Complete the summary below.
Choose NO MORE THAN TWO WORDS from the passage for each answer.
Rethinking the sources of water
The destruction of the airship Hindenburg in 1937 was a lesson in the danger of hydrogen combusting. If water 18 ……….. were to be ended by using the chemical reaction of putting oxygen and hydrogen together, the risks would need to be carefully managed. Using 19 ……. has proven to be a dangerous form of energy production, yet countries still continue with it. The value of creating water supplies may also be seen as a risk worth taking.
Water supplies can also be obtained through the 20 ………… of seawater. The long established way of doing this is the distillation process, but it is costly. Another method called 21 ………… , is currently used to supply Dubai with water, and electro-dialysis is a further option.
BEST IELTS Academic Reading Test 236
Questions 22-26
Do the following statements agree with the information given in Passage 2?
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
22. Wealthier countries should fund the water production required by lower income nations.
23. Solar distillation needs to be made more ecologically beneficial.
24. Using water vapour as a water supply is an option that shows potential.
25. Machines that produce water from vapour have issues that are similar to desalination.
26. The writer concludes it is unlikely that a feasible solution will be found.
BEST IELTS Academic Reading Test 236
ANSWERS ARE BELOW
BEST IELTS Academic Reading Test 236
ANSWER
14. PATHOGENES
15. A FIFTH
16. THE ELECTRONS
17. A MASSIVE EXPLOSION
18. SHORTAGES
19. NUCLEAR POWER
20. DESALINATION
21. REVERSE OSMOSIS
22. NOT GIVEN
23. FALSE
24. TRUE
25. TRUE
26. FALSE
BEST IELTS Academic Reading Test 236