Part of The Student Room Group

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

Chem MC analysis. In which of the following cases may it obtain a complete neutralization? (1)25.0 cm3 of 0.120 M sulphuric acid and 50cm3of 0.120M sodium hydroxide solution (2)50.cm3 of 0.5 M Sodium hydroxide and 0.025 moles of aqueous ammonium chlorid

Extracts from this document...

Introduction

Chemistry 4A Ivan Liu Chun Pok (12) Non-practical task Mc analysis Topics: Neutralization, Reaction between alkali and ammonium compound, Strength of Acid and Alkali, Reacting Masses, Volumetric Analysis In which of the following cases may it obtain a complete neutralization? (1)25.0 cm3 of 0.120 M sulphuric acid and 50cm3of 0.120M sodium hydroxide solution (2)50.cm3 of 0.5 M Sodium hydroxide and 0.025 moles of aqueous ammonium chloride (3)20.0cm3 of 0.100M phosphoric acid and 30.0cm3 of 0.200 M potassium hydroxide solution (4)Dissolve 0.2025g of solid sodium hydroxide in water and make up to 250cm3 of solution, then 25.0cm3 of this solution is added to 50.0cm3 of 1M hydrochloric acid A.2 B.1, 3 C.3, 4 D.1, 2, 4 Option 1: H2SO4(aq) + 2NaOH(aq)--> Na2SO4(aq) +H2O(l) Mole ratio of H2SO4 : NaOH = 1:2 ?Using the formula, Molarity of a solution M or mol dm-3 = Number of moles of solute (mol) / Volume of solution (dm3) ?Number of moles of solute (mol) = Molarity of a solution M or mol dm-3X Volume of solution (dm3) ...read more.

Middle

ions. Also, they may over-focus on the concept that weak acid can react with strong alkali to produce acidic salt, instead of normal salt. e.g : H3PO4(aq) + NaOH(aq)--> NaH2PO4(aq) +H2O(l) H3PO4(aq) + 2NaOH(aq)--> Na2HPO4(aq) +2H2O(l) These above reactions are absolutely correct, but we have to answer carefully for what the question asks.It said 'In which of the following cases may it obtain a complete neutralization?' It is not necessary for the salts produced is acidic, we cannot eliminate the case that normal salt is formed. Whether the neutralization is complete or not can only be determined by mole calculation. H3PO4(aq) + 3KOH(aq)--> K3PO4(aq) +3H2O(l) Mole ratio of H3PO4: KOH = 1:3 Using the formula, ? Molarity of a solution M or mol dm-3 = Number of moles of solute (mol) / Volume of solution (dm3) ?Number of moles of solute (mol) = Molarity of a solution M or mol dm-3 X Volume of solution (dm3) Number of moles of H3PO4 given: 0.100 X (20.0 /1000) ...read more.

Conclusion

If a student chooses A, it means he has wrong concepts on mole calculation (reacting masses and volumetric analysis), neutralization and strength of acid and alkali. If a student chooses C, it means he has wrong concepts on mole calculation (reacting masses and volumetric analysis). If a student chooses D, it means he has wrong concepts on strength of acid and alkali. To conclude, The steps to tackle this question are as follows: 1) See if there are reactions that are not considered as neutralization first. Option (2) can be eliminated instantly, thus the correct answer can only either be B or C. 2) In both answers B and C, we can see that option (3) is included so it implies that options (3) must be correct. It is unnecessary to determine whether it is correct or not by mole calculation. 3) We only need to determinate whether options (1) and (4) is correct or not based on mole calculation. If the calculation is correct, we can deduce that option (1) is correctwhereas option (4) is incorrect. 4) Finally we can conclude that only options (1) and (3) are correct, which lead to the fact that the correct answer should be B. ...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

or


Here's what a teacher thought of this essay

5 star(s)

*****
Clear, step by step calculations and analyses of the four reactions. The author demonstrates a detailed understanding of the chemistry involved and possible pitfalls.

Marked by teacher Adam Roberts 14/10/2013

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. The rate of reaction between magnesium and sulphuric acid.

    The graph indicates that if you double the concentration the rate of reaction doubles, this proves my prediction correct. If there is an increase in the number of particles in the solution it is more likely that they will collide more often.

  2. Acid-Base titration of Sulphuric acid and Sodium Hydroxide

    DEPENDENT VARIABLE The dependent variable in this experiment is the volume of sulphuric acid from the burette that was used to neutralize the base.

  1. Investigate a neutralisation reaction between hydrochloric acid and sodium hydroxide.

    To collect my evidence needed I will need to have the same volume of acid and alkali each time. Both the acid and alkali will measure 10cm3 each time. The two solutions will both be poured in a polythene cup to measure the temperature of the solutions when reacting.

  2. Standardization of NaOH and Analysis of Unknown Acid Sample.

    Once the solution is a steady, pale pink (one which does not fade upon swirling), the solution has been properly titrated. 11. Repeat the titration of the remaining two samples of KHP. 12. Calculate the number of moles in each sample, given that the molecular weight of KHP is 204.2g.

  1. Preparation of Potassium Trioxalatoferrate (III)

    sulphate = 4.95g hydrated ammonium iron (II) sulphate - n = m/GFM = 4.95/392 = 0.0126 moles 0.0126 moles (NH4)2Fe(SO4)2.6H2O --> 0.0126 moles FeC2O4 0.0126 moles FeC2O4 --> 0.0084 moles K3[Fe(C2O4)3].3H2O Mass of clock glass = 14.46g Mass of clock glass + crystals = 16.26g Mass of potassium trioxalatoferrate (III) crystals = 1.8g hydrated potassium trioxalatoferrate (III)

  2. Determine Solubility of KClO3 Salt.

    Gases Formula Solubility g/100-mL Temperature /K Ammonia NH3 51.8 293 Carbon dioxide CO2 0.145 298 Hydrogen chloride HCl 82.3 273 Nitrogen N2 0.0019 293 Oxygen O2 0.0043 293 Solids Formula Solubility g/100-mL Temperature /K Aspirin HC9H7O4 0.33 298 Baking soda NaHCO3 10 298 Caustic soda NaOH 42 273 Marble CaCO3

  1. Determine the formula of hydrated Sodium Carbonate

    moles of H2O. The second method I will use to determine x, will involve a titration between hydrated sodium carbonate and hydrochloric acid. Na2CO3 + 2HCl --> 2NaCl + CO2 + H2O 0.1M Hydrochloric acid Hydrated Sodium Carbonate Phenolphthalein Indicator Distilled water Burette (50 cm3)

  2. Indirect determination of enthalpy change of decomposition of sodium hydrogen carbonate by thermochemical measurement ...

    by using: heat absorbed / moles. This represents ?H1 with reference to our reaction cycle: Molar ?H = heat absorbed by solution (J) = +992.75= +26125 J/mol-1 = Moles NaHCO3 0.038 = +26.13 kJ/ mol-1 Procedure for Experiment 2: with sodium carbonate Initially, I gathered all the necessary apparatus together and set up my calorimeter, as with the previous experiment.

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