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

Observation exercise on the compounds of the s-block elements

Extracts from this document...

Introduction

Observation exercise on the compounds of the s-block elements You are provided with 3 salts X, Y and Z which each contain a different s-block element. Carry out the reactions listed. Report all your observations and deductions in the table. You are not expected to write equations for the reactions. 1. Heat about 0.5g of solid X in a clean dry test tube and test the gas evolved with a glowing splint. Continue heating strongly until there is no further change and allow the residue to cool. Observation Inference The salt changes state from a white solid to a clear liquid. Bubbles are given off and the gas released re-lights a glowing splint. Cooled residue is pale in colour. The presence of oxygen within the salt compound. 2. Use a fume cupboard for this test. Add 2 cm3 dilute hydrochloric acid to the cooled residue. Identify the gas evolved. Observation Inference The acid reacts with the cooled residue and releases brown gaseous fumes into the air. A solid residue and a clear liquid remains in the test tube. It would be reasonable to assume that the gas is poisonous as the instructions indicate the strict use of the fume cupboard. ...read more.

Middle

5. Add 1 cm3 of dilute hydrochloric acid to the cooled residue. Observation Inference The dull grey creamy solid reacts energetically with the hydrochloric acid and produces bubbles, which indicate the releasing of a colourless gas. The reaction forms a white residue along with a clear liquid at the bottom of the test tube. If the salt does contain either a metal carbonate or a metal hydrogen carbonate then a reaction with an acid would be energetic and form a salt, water and carbon dioxide. The gas in this reaction is likely CO2 and the remaining white residue a salt with the clear liquid being water. Group 1 carbonates exist as solids whereas you will only find group 2 carbonates in solution. I believe we are looking for a group 1 carbonate. 6. Make a solution of about 0.5g of solid Y in 5 cm3 of distilled water and divide the solution into two equal parts: a) To the first part, add 1 cm3 of silver nitrate solution followed by an equal volume of dilute nitric acid. Observation Inference The silver nitrate turns the solution a milky cream colour with obvious signs of white and yellow residue in the liquid. ...read more.

Conclusion

Indicating that the salt contains just a chloride. 8. Identify the cations in X, Y and Z using flame tests. Observation Inference X - Lilac flame Y - Orange and Yellow flame Z - Brick Red flame The presence of potassium as the K+ ion. The presence of sodium as the Na+ ion. The presence of calcium as the Ca2+ ion. 9. Make a solution of 1.0g of Y in 5 cm3-distilled water and add it to a solution of 1.0g of Z in 5 cm3-distilled water. Heat the mixture. Observation Inference The combined solutions bubble quickly in a blue flame and the solution boils over the test tube. Heavy concentration of a cloudy grey gas released, which puts out a flame. If solution Y is sodium hydrogen carbonate and solution Z is calcium chloride then when I heated the combined solutions the products would be Calcium Carbonate, Sodium Chloride, water and carbon dioxide in the equation: 2NaHCO3 (aq) + CaCl2 (aq) CaCO3 (aq) + 2NaCl (aq) + H2O (l) + CO2 (g) This would explain the concentration of the gas released, which would be composed of carbon dioxide capable of putting out a flame and some water vapour. Write the formulae of: X Y Z KNO3 NaHCO3 CaCl2 Chemistry Coursework Nick Curum Compounds of the s-block elements 1 27/04/2007 ...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 Aqueous Chemistry 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 Aqueous Chemistry essays

  1. To investigate the rate of reaction between different concentrations of hydrochloric acid with metal ...

    If any does stick, use a tissue to wipe it clean, so that there is no impedance of the stopper. 4. To counter the problem wipe the inside of the syringe using tissue after each experiment to relieve most of the stickiness and make sure all the connections are tight, so no leakage is being done.

  2. Organic observation exercise

    Compound X is likely to be an aldehyde other than ethanal, as it did not prove positive for this test. Compound Y OBSERVATIONS INFERENCES The brown solution of iodine is combined with 1 drop of NaOH and compound Y to produce a beige-yellow colour which after discharging smells of anti-septic.

  1. identifying an unknown compound

    HCl] To 1 ml of the unknown compound in a test tube add 6 mls of Lucas' reagent at room temperature. Close the tube with a cork, shake properly and then allow to stand. Very fast reaction and droplets of alkyl chloride formed almost immediately For Primary alcohols there is

  2. Organic compound identification.

    A normal individual roughly excretes between 28 and 30g of D per day. The following information was given to help find the Mr and MF of D. Compound D can be completely hydrolysed in the presence of a suitable enzyme. One mole of water will hydrolyse one mole of D.

  1. Investigate 'How much gas is released when a metal reacts with an acid.'

    + 32 (the mass of the sulphur) + 16 � 4 (the mass of the 02). You then work out how much you will need for a certain amount of Magnesium: 24g of Magnesium will need 98g of H2SO4 0.24g of Magnesium will need 9.8g of H2SO4, and 0.024g will need 0.098g of H2SO4.

  2. The Group VII elements - Halogens

    The forces increase as you go down the group. As the atomic number of an element increases, the element becomes more POLARIZABLE and the instantaneous dipole - induced dipole forces become stronger. This is because, as the number of electrons increases, so too does the likelihood that the charge distribution of an atom will not be symmetrical.

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