• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Bateries reasearch task

Extracts from this document...


B) Evaluate the DRY CELL in comparison to a SILVER BUTTON CELL in terms of chemistry, cost and practicality, impact on society and environmental impact. DRY CELL SILVER BUTTON CELL Chemistry NEGATIVE TERMINAL: Zn --> Zn2+ + 2e- POSITIVE ELECTRODE: NH4+ + MnO2 + H2O + e- -->Mn(OH)3 + NH3 VOLTAGE: Approximately 1.50 volts ELECTROLYTE: NH4Cl and ZnCl2 paste ANODE: 2MnO2 (s) + H2O (l) + 2e- -->Mn2O3 (s) + 2OH- (aq) CATHODE: Ag2O(s) + H2O(l) + 2e- --> 2Ag(s) + 2OH-(aq) VOLTAGE: Approximately 1.55 volts ELECTROLYTE: KOH and Zn (OH)2 Cost & Practicality * Relatively inexpensive * Releases small voltage * Small and easy to store and use * Maintains constant voltage of a period of time * Not rechargeable * Short term uses only * Can not deliver high current * Battery may leak due to the zinc casing being used up in chemical reaction. * Short shelf life as acidic paste attacks the zinc casing USES: Toys, torches, portable radios * Expensive as it includes silver * Not rechargeable * Produces a significant amount of current * There is a constant voltage over a long period of time * Small size enables its use in delicate and portable devices. ...read more.


A paste of potassium hydroxide separates the two substances and acts as a porous medium. At the negative terminal the zinc oxides in an aqueous solution with hydroxide ions to form zinc oxide and water, whilst at the positive terminal silver oxide and water reduce to form silver solid and hydroxide ions. The cell has an overall voltage of 1.3V. Oxidation: 2MnO2 (s) + H2O (l) + 2e- -->Mn2O3 (s) + 2OH- (aq) Reduction: Ag2O(s) + H2O(l) + 2e- --> 2Ag(s) + 2OH-(aq) In terms of chemistry both cells differ greatly from the reactant to size and shape. The dry cell however has a slightly higher voltage than the silver button cell. Both cells have positives and negatives in relation to there cost and practicality. A positive aspect in both cells is that a voltage is maintained over a long period of time, a negative however is that in the dry cell this voltage is lower than in the button cell. The button cell can deliver high currents where as the dry cell can not. ...read more.


It would also have an impact on society as the workers who are exposed to the heavy metal and corrosive substances are more susceptible to developing abnormalities which can be fatal, such as cancer. Similarly in the button cell silver has major impacts on aquatic life. If was found the high levels of silver can lead to decreased major organ functions and is particularly lethal to aquatic plant species. The button cell also contains the corrosive substance potassium hydroxide which also causes abnormalities in organisms in high concentrations. In comparing the two cells in cost and practicality, impact on society and environmental impact, the silver cell has some important advantages over the dry cell. The silver button cell has much longer life than the dry cell. That is it can deliver a consistently higher voltage over a greater period of time, this is especially important in medical devices. The silver button cell is also less likely to leak thus less chance of having detrimental effects on the environment. Overall the silver button cell has the properties of the dry cell and other features which enables its use in a diverse range of situations. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Classifying Materials section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Classifying Materials essays

  1. Hydrogen-Oxygen Fuel Cells: Case Study

    Some modern cars (as well as buses and trucks) are run by hydrogen fuel cells as well, however due to limited availability of hydrogen and the cost of fuel cells, this is not a common occurrence. Uses of the cell (in relation to its properties)

  2. An experiment to investigate the factors that determine the amount of energy released when ...

    I experimented with 1.02g of hexan-1-ol and 25cm3, 75 cm3, 100 cm3 and 150 cm3 and I used my results from my previous experiment for 50 cm3. I used a 100ml conical flask for 25cm3 and 75cm3 and a 200ml conical flask for 100cm3 and 150 cm3.

  1. Elements of life.

    part of a giant ionic lattice where each positive ion is attracted by two negative ions. Covalent bonds Covalent bonds occur because it is not energetically favourable to bond ionically, and so two atoms share a pair of electrons, the electron pair creates a bond between the two atoms because

  2. Our experiment consisted of two samples of water containing unknown substances, and our objective ...

    - ? = 1.88g ?after desiccating = ? - ? = 1.65g Apparatus diagrams Reliability in stage 1 Our experiment was quite reliable. There were not many things that could go wrong. However, when we tested sample A I don't think our experiment was reliable, since there was absolutely no solid whatsoever left in the evaporating basin after evaporating.

  1. material science unit 2 task 1

    the positive charge of the atoms' nuclei and the negative charge of their electrons. chemicals that bond using covalent bonding are usually gases or liquids at room temperature. e.g. Elements: chlorine (Cl), hydrogen (H) Compounds water (H2O), Hydrogen chloride (HCl), Ammonia (NH3).

  2. material science unit 2 task 2

    and the rest are Silicides (silicon compounds). Structure: They are made of a mixture of metal and non-metal atoms. (Compounds). Atoms in ceramics bond using ionic and covalent bonding. Their atoms and molecules are composed of 2 or more different types of electrons, protons and neutrons. For example Barium Titanate ( BaTiO3 )

  1. GCSE Chemistry - Obtaining Zinc Oxide from Calamine

    it so you can move the oxygen atom to CO2, which will make it CO3 so that makes the equation ZnCO3. Now I have all the different RFM's of all the different elements, I can use these to do the equations that I need to do.

  2. Variability of Relative Stability of Oxidation States.

    However, they are not the most stable forms. Carbon's 0 oxidation state is the most stable form at a particular condition that if the substance is diamond ( It is formed by carbons). Oppositely, if the condition is that the carbon forms the graphite, it will not be the most stable form.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work