Hard and Soft Water

Hard and Soft Water
Hard water is made when water runs over or through landscape containing calcium ( Ca ) and magnesium (mg ) ions. These materials dissolve into the water making it hard. If rain water falls on limestone or chalk ? CaMg (CO ) (this is the common form of limestone which contains both ca and mg ions. Some forms of limestone contain only one of these materials but the result is just the same) then the carbonic acid present causes a reaction Ca CO +H CO Ca (hco ) MgCO + H CO My(hco ) Calcium Hydrogen carbonate and magnesium hydrogen carbonate [Ca(H(O ) ] isn?t strongly soluble in water and therefore it forms temporary hard water. If rain water falls on gypsum (calcium sulphate) then the gypsum dissolves to make a solution known as hard water: Ca SO +H O Ca (hso ) Properties of hard water ======== Water has a layer on top of it known as surface tension, here there are weak van-der-wall forces that hold the molecules together, making a weak curved effect. This layer is unreactive and also makes it impossible for soap to react with the water to form lather. In permanent hard water this layer cannot be broken by soap and therefore will not react with it but will form a layer of scum. The lower the concentration of hard water the softer the layer will be and therefore it will be easier for the soap to react with the water to form lather.

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Investigation of Factors Affect Osmosis in Potatoes

Investigation of Factors Affect Osmosis in Potatoes
Aim The aim of the following experiment was to investigate the effect of varying the concentration of sucrose solution on osmosis in a potato. Preliminary Experiments One preliminary experiment was done before the main experiment. From the preliminary, we were trying to find out how osmosis actually occurred in potatoes, and gave us a vague idea on what the main experiment would be like. This preliminary will aid my prediction, which is stated below. The following apparatus was used for the preliminary:

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The Water Condition of the Brisbane River

The Water Condition of the Brisbane River
The Brisbane River has flowed for over 400 million years. The catchment of the Brisbane River has overcome phases of flood and drought while its origins altered as the surrounding land changed overtime.

In 1823, John Oxley entered the river for the first time. At the time the river appeared clean and unpolluted. Oxley immediately recognised the river?s potential as a site for new settlement, through his recommendation the city of Brisbane was established in 1825. The Brisbane River extends inland for 300km reaching its source at the foothills of the Great Dividing Range. The river?s catchment occupies an area of approximately 30,000km2 and releases it waters into Moreton Bay. The once pristine waters were used as a source of drinking water and recreational purposes. Industries saw the river as a cheap and efficient source for waste discharge. Before road links were established with Sydney the river held the only form of transport including trade. The Brisbane River was and still is the cities most valuable asset for both recreational, relaxational and transportational purposes.

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Trolley Investigation

Trolley Investigation
Choosing a Variable Before I begin the investigation, I must first decide which variable I should investigate. Variables can be divided into 2 major groups: dependant variables and independent variables. In measuring the behaviour of a trolley the dependant variable is speed. This is because the speed will change when other variables are changed. An independent variable is a variable which cannot be affected by other variables. There are many independent variables in measuring the behaviour of a trolley and I must first assess which one would be a suitable one to investigate:

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Investigation of Rate of Reaction

Investigation of Rate of Reaction
I will be conducting an experiment on the rate of reaction for my gcse coursework. . We will be reacting sodium thiosulphate with hydrochloric acid. I will be investigating the effects had on rate of reaction. When sodium thiosulphate and hydrochloric are mixed, a yellow precept of sulphur is produced. The solution becomes increasingly difficult to see through as more and more sulphur is formed. what IS rate OF reaction? The rate of reaction tells us how quickly a chemical reaction happens. Rate is measuring of the change that happens in a single unit of time. Cause its not enough to know if a reaction is fast or slow. We can?t work out the rate of reaction from its chemical equation. Equations can only tell us how much product we can get. They don?t say how quickly it is made. We can only find the rate by actually doing experiments. During a reaction, we can measure how much reactant is used up in a certain time. On the other hand, we might choose to measure how much product is formed in a certain time. The factors that affect the rate of a chemical reaction are: Â? Temperature Â? Surface area Â? Catalyst Â? Concentration Â? Pressure (only occurs in gases) aim - A reaction can be made to go faster or slower by changing the temperature of the reactants A reaction goes faster when the temperature is raised.

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Tourism in The Isle of Purbeck

Tourism in The Isle of Purbeck
Tourism does more harm than good in The Isle of Purbeck Of Purbeck. Tourism should not be promoted or encouraged. where IS IT? ==== Swanage is in the Isle of Purbeck, Dorset. The Isle of Purbeck is known to many different kinds of facilities to suit everyone?s needs, one of the most populist features that The Isle of Purbeck has to offer is the award winning beaches. Because of the various types of attractions The Isle of Purbeck has to offer, it is known as a ?honeypot site?

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Exploring Enzymes and Micro-Organisms

Exploring Enzymes and Micro-Organisms
All most all enzymes used commercially are obtained from
microorganisms. The microorganisms are grown or cultured and the
enzymes extracted or harvested from them.

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Geography As Environmental Investigation

Geography As Environmental Investigation
As part of my AS Geography course, I am required to carry out an environmental investigation of an area of my choice. In order to complete this investigation, I will need to carry out further extensive research such as questionnaires and environmental quality scores, which will support my statements in my hypothesis. The area that I have chosen is Shepherds Bush, West London. Here a new shopping/cinema complex has recently been built, which may affect the eqs of some areas. Questions: 1. How can Environmental Quality be defined. 2. How does environmental quality vary in the area. 3. Has management in London improved the environmental quality of the area

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The Effect of PH on Enzyme Activity

The Effect of PH on Enzyme Activity
Enzymes are known as biological catalysts. They are widely used in today?s world to alter or speed up the rate of reaction without themselves being changed. Enzymes are globular proteins which act as catalysts. A catalyst is a chemical substance, which speeds up the rate of reaction. For an example in the human body there are several thousands of chemical processes going and the quicker these happen the better it is, so enzymes are produced to increase the rate of reaction

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The Aral Sea Disaster

The Aral Sea Disaster
The Aral Sea is located on the board between south Kazakhstan and north Uzbekistan. The Aral Sea is in central Asia, 500 km to the east of the Caspian Sea. It uses to be the fourth largest lake in the world and in its natural state covered an area off 66,458 sq.km, three times the size of Switzerland. The nearest major city is Tashkent, which has a population of 2,077,000. The Aral Sea has a desert continental climate it has hot summers with average July temperature above 23c and cold winters with an average temperature below -5c. The water in the Aral Sea freezes during the winter. Precipitation is about 100 mm per year. The Aral Sea is in the centre of a large, flat desert basin. In the picture to the left shows where the Aral Sea is located. What happened to the Aral Sea? The Aral Sea region is big cotton farming area. The Amu Darya and Syr Darya rivers flow through cotton farmland into the sea. In the 1950s, the Soviet government decided to divert some of the water from these rivers to irrigate the cotton fields. As more water was diverted for agriculture, less and less river water flowed into the sea. [image] The Soviet Union was in control of the Aral Sea area and they decide that they needed a reliable source of cotton because it had poorly developed synthetics fibre industry. It therefore had to rely on natural fibres for its textiles industry.

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