Question

Part III. Single Replacement. With the following reactions, evidence of a reaction may not be immediately apparent. Before making a decision be sure to let the reaction stand for approximately 10 minutes. If no reaction occurs, write, "NO RXN" in under balanced chemical equations; Do not Wrile products or other equations. 1. Fill a test tube half full with DI water and place it behind the safety shield in the hood. Sodium metal is stored under a non-reactive solvent such as hexane or oil. Take a small piece of sodium from the stock bottle and place it on a piece of filter paper, being careful not to touch it with your hands. Blot the sodium with the filter paper. As you blot the sodium, apply pressure. Using tongs or tweezers pick up the piece of sodium and drop it into the test tube of water, con- currently ignite a splint. While the reaction is proceeding quickly take a burning splint and bring it to the mouth of the test tube as the sodium is reacting. Carefully note your observations. Use a stir rod to mix your solution and put a drop on red litmus paper. Phenolphthalein is an acid/base indicator, which is colorless in acid solution (contains H' ions) and is bright pink in base solution (contains OH ions). Put a few drops of phenolphthalein into the test tube. TABLE 9.8 Observations sodium metal and water The ficce in tue tult tulee SMOKE was obsened ted neay fast /fizzed CivCing justwnun t plint wac Placed in oping bepan a Sound of was cxpenen ceel. a. Is the sodium malleable? b. What happened when the sodium was placed in water! C. What gas do you think was evolved? Explain your answer using your observations. hydvogen stvang Seels d. What color does red litmus paper turn? Is the solution acidic or basic! Blue basic Colution e. What color is the reaction solution once the phenolphthalein is added? 14 turned furpC Pot pink f Does the solution contain hydrogen ions, H', or hydroxide ions, OH? YCs a layer was fommed ott urface hydvocyen 1onS H+ Reactants Products Sation Balanced Chemical Equation Total lonic Equation Net lonic Equation

Answer 1

Table 9.8:

The reaction of sodium metal with water is analysed as per the above provided information in the question. The following observation are made by answering all the required subquestion as below.

a) The sodium metal is malleable which can be beaten into sheets. This is due to the energy is transferred throughout the rest of the metal by the moving electrons.

b) When sodium is placed in water, It reacts rapidly with water to form a colourless solution of sodium hydroxide (NaOH) and hydrogen gas (H₂). It is highly exothermic reaction and the heat /energy evolved during the reaction ignites the H₂ gas and the metal explodes because it loses its valence electron in water.

c) As explained in b, the hydrogen (H₂) gas is generated during the reaction. The heat or energy evolved in the reaction ignites the H₂ gas with spontaneous fire and explosion.

d) In this reaction the colurless solution formed is because of NaOH solution which is highly basic in which the red litmus paper turn dark blue in colour.

e) When the phenolphthalein indicator is added to the reaction solution, the resulting NaOH solutions changes the clear to pink colour.

f) The resulting solution only contains hydroxide ions concentration (OH^-)

Reactants: Sodium metal (Na) and water (H₂O)

Products: Sodium hydroxide solution (NaOH) and hydrogen gas (H₂) evolved.

Please find the explanation on the 1. balanced chemical equation , 2. total ionic equation and 3. net ionic equation in the below image.

Date Reaction of sodium metal with water. 1. Balanced chemical equation 2Nac) + 2H20 w 2NaOH cag) + H29) 2 Total Tonic equation , 2nas + 2H204) -> 2Nacaat ott (94) + H2 CV) As there is no spectator ion on the berth side a reaction de no any common icns are present thestere net ionic equatros for the above reactron is same as that of complete (total) ionic equation. -3. Het ionic equation 2Na+2400 > Nacant OHlaa) H₂ Cg