A is a solution containing 0.050 mol. dm of tetraoxosulphate (VI) acid. B is a solution of anhydrous trioxocarbonate (IV).
(a) Put A into the burette and titrate with 20cm\(^3\) or 25cm\(^3\) portions of B using methyl orange as an indicator. Record the volume of your pipette. Tabulate your burette readings and calculate the average volume of A used
(b) From your results and the information provided, calculate the:
(i) Concentration of solution B in mol. dm\(^{-3}\)
(ii) mass of sodium tetraoxosulphate (VI) that would be formed in solution of 1dm\(^3\) of solution B were neutralized by solution A
(iii) volume of carbon (IV) oxide at s.t.p. that would be liberated in (b)(ii) above. The equation for the reaction is: N\(_2\)CO\(_{3(aq)}\) + H\(_2\)SO\(_{4(aq)}\) \(\to\) Na\(_2\)SO\(_{4(aq)}\) + H\(_2\)O\(_{(l)}\) + CO\(_{2(g)}\) [O = 16; Na = 23, S = 32; molar volume of gases of s.t.p. = 22.4dm\(^3\)
C and D are samples of two different simple salts. Carry out the following exercises on them. Record your observations and identify any gases evolved. State the conclusion you draw from the result of each test.
a) Heat about one-half of C in a dry test tube until no further change is observed. Allow to cool.
(b)(i) To the cooled residue from (a) above, add about 5cm\(^3\) of dilute hydrochloric acid and warm.
(ii) To about 2cm\(^3\) of the clear solution from (b)(i) above add aqueous ammonia in drops until it is in excess.
(c) Put all of D in a boiling tube and add about 10cm\(^3\) of distilled water. Shake thoroughly and divide into two portions.
(d)(i) To the first portion from (c) above, add about 2cm\(^3\) of barium chloride solution, followed by dilute hydrochloric acid in excess. Warm the mixture.
(ii) To the second portion from (c) above, add 2 or 3 of acidified potassium tetraoxomanganate (VII) solution and shake.
(a) Draw a labelled sketch of the laboratory set-up for dissolving hydrogen chloride acid.
(ii) Give one chemical test to distinguish between hydrochloric acid and ethanoic acid
(b) Outline a suitable laboratory procedure for obtaining a fairly pure sample of sodium chloride crystals from a solution of it that is contaminated with some methyl orange:
(c) Name one substance used in the laboratory for:
(i) drying ammonia gas,
(ii) testing for the presence of water;
(iii) converting copper (I) oxide to copper.
All your burette readings (initial and final), as well as the size of your pipette, must be recorded but no account of experimental procedure is required. All calculations must be done in your answer book.
A is a solution containing 6.3g dm\(^{-3}\) of impure ethanoic acid. B is 0.10mol. dm\(^{-3}\) sodium hydroxide sodium hydroxide solution.
(a) Put A into the burette and titrate with 20.0cm\(^3\) or 25.0cm\(^3\) portions of B using phenolphthalein as indicator. Record the volume of your pipette Record the volume of your pipette. Tabulate your burette readings and calculate the volume of A used.
(b) From your result and the information provided, calculate the
(i) concentration of solution A in mol.dm\(^{-3}\)
(ii) Concentration of solution A in dm\(^{-3}\) and hence the percentage purity of the ethanoic acid,
(iii) Volume of solution A that would neutralize a solution containing 0.005 mole of sodium hydroxide. The equation for the reaction is;
H\(_2\)C\(_2\)O\(_{4(aq)}\) + 2NaOH\(_{(aq)}\) \(\to\) Na\(_2\)C\(_2\)O\(_{(aq)}\) + 2H\(_2\)O\(_{(l)}\) [H = 1; C = 12. O = 16]
(c)(i) What would be the colour of methylorange indicator in solution B?
(ii) Give the reason why methylorange is not a suitable indicator for titration.
Credit will be given for strict adherence to instructions, for observations precisely recorded, and for accurate inferences. All tests, observations, and inferences must be clearly entered in your answer book, in ink at the time they are made.
C is a mixture of two simple salts. Carry out the following exercises on C. Record your observations and identify any gases evolved. State the conclusion you draw from the result
(a)(i) Put all C in a boiling tube or beaker and add about 10cm\(^{3}\) of distilled water Stir the mixture thoroughly and tilter Keep both the residue and the filtrate
(ii) Test the filtrate with litmus paper.
(b) Divide the filtrate of two portions
(i) To the first portion of the filtrate. add about 2cm\(^3\) of dilute trioxonitrate (v) acid and then silver trioxonitrate (v) solution
(ii) To the second portion of the filtrate, add sodium hydroxide solution in drops until it is in excess.
(c) Put half of the residue in a test tube and heat strongly. Allow to cool
(d)(i) Put the remaining half of the residue in a test tube and add about 2cm\(^3\) of dilute hydrochloric acid.
(ii) To the resulting solution from (d(i)) above, add aqueous ammonia in drops until it is in excess.
(a) Use the following reaction scheme to answer Questions;(i) – (iii) below;
(i) Give one suitable procedure for carrying out each of reactions 1, 2, and 3 separately in the laboratory
(ii) State the gases produced along with lead (lI) Oxide in reaction 1.
(iii) What is the colour of lead (II) tetraoxosulphate (VI)?
(b) When a drop of concentrated trioxonitrate (V) acid was added to potassium iodide solution, a violet-colored gas was evolved?
(i) What is the name of the gas evolved?
(ii) State the functions of concentrated trioxonitrate (V) acid in the reaction.
(iii) What would be observed if starch solution were added to the reaction mixture?
All your burette readings (initial and final), as well as the size of your pipette, must be recorded but no account of experimental procedure is required. All calculations must be done in your answer book.
A is a solution of tetraoxosulphate (VI) acid. B is a solution containing 1.4g of potassium hydroxide per 250cm\(^3\)
(a) Put A into burette and titrate with 20.0cm\(^3\) or 25.0cm\(^3\) portions of B using methyl orange or screened methyl orange as indicator. Record the volume of your pipette. Tabulate your burette readings and calculate the average volume of A used.
(b) From your results and the information provided, calculate the:
(i) concentration of B in mol.dm\(^{-3}\)
(ii) concentration of A in mol dm\(^{-3}\)
(iii) number of hydrogen ions in 1.0dm\(^{-3}\) of A. The equation for the reaction is: H\(_2\)SO\(_4\) + 2KOH \(\to\) K\(-2\)SO\(_4\) + 2H\(_2\)O. [H= 1, O = 16; K = 39. Avogadro constant = 6.0 x 10\(^{23}\)]
(c) State whether the pH of the following would be equal to 7, greater than 7 or less than 7
(i) Solution A:
(ii) Titration mixture of A and B before the endpoint
Credit will be given for strict adherence to instructions, for observations precisely recorded, and for accurate inferences. All tests, observations, and inferences must be clearly entered in your answer book, in ink at the time they are made.
C and D are samples of two simple salts. Carry out the following exercises on them. Record your observations and identify any gases evolved. State the conclusion you draw from the result of each test.
(a) Put all of C in a test tube and heat strongly for about 3 to 5 minutes. Allow the residue to cool.
(b) Add about 5cm\(^3\) of distilled water to the residue from (a) above. Shake and test with litmus paper.
Mention one suitable laboratory procedure for
(i) removing carbon (IV) oxide from a sample of air
(ii) determining whether a given sample of water is pure or not;
(iii) concentrating a dilute solution of sodium chloride.
(b) Use the information provided in the table below to outline a suitable procedure for separating a mixture containing P, Q and R into its Components.
| Component | Solubility in tetrachloromethane | Solubility in water |
|
P Q R |
Insoluble Soluble Insoluble |
Insoluble Slightly soluble soluble |
(c)(i) Draw a labelled sketch to illustrate the collection of gases by upward displacement of air.
(ii) A gas S, with a rotten egg smell, was evolved when dilute hydrochloric acid was added to T which is a salt of iron (II). S decolorized acidified potassium tetraoxomanganate (VIl) solution and a yellow precipitate V was also obtained. Identify S, T and V.
(iii) State what would be observed on bubbling chlorine through a solution of potassium bromide.
All your burette readings (initial and final), as well as the size of your pipette, must be recorded but on no account of experimental procedure is required. All calculations must be done in your answer book.
A is 0.50 mol dm\(^{-3}\) hydrochloric acid. B is 0.025 mol dm\(^{-3}\) of a trioxocarbonate (IV) salt.
(a) Put A into the burette and titrate with 20.0cm\(^{-3}\) or 25.0 cm\(^{-3}\) portions of B using methyl orange or screened methyl Orange indicator. Record the volume of your pipette. Tabulate your burette readings and calculate the average of A used.
(b) From your results, calculate the mole ratio of acid to trioxocarbonate (IV) in the reaction, expressing your answer as a whole number ratio of one.
(c) Given that B contains 7.2g dm\(^{-3}\) of the hydrated trioxocarbonate (IV) salt, calculate the:
(i) concentration of anhydrous salt in B in g dm\(^{-3}\) [Molar mass of anhydrous salt in B = 106g]
(ii) percentage of water of crystallization in the hydrated salt.
Credit will be given for strict adherence to instructions, for observations precisely recorded, and for accurate inferences. All tests, observations, and inferences must be clearly entered in your answer book, in ink, at the time they are made.
C and D are samples of two simple salts. Carry out the following exercises on them. Record your observations and state the conclusion you draw from the result of each test.
(a)(i) Put half of C in a test tube and add about 5cm\(^3\) of distilled water. Test with litmus.
(ii) Put the rest of C in a test tube and add about 5cm\(^3\) of dilute hydrochloric acid. Identify any gases evolved.
(b)(i) Put half of D in a test tube. Add about 5cm\(^3\) of sodium hydroxide solution and warm. Identify any gases evolved.
(ii) Put the rest of D in a test tube and add about 5cm\(^3\) of distilled water. Mix thoroughly. Add about 2cm\(^3\) of barium chloride solution, followed by dilute hydrochloric acid in excess.
(a) Name one laboratory apparatus/set-up for:
(i) determining the heat of neutralization:
(ii) decomposing water into hydrogen and oxygen.
(b) Outline a suitable procedure for distinguishing between glucose and cellulose using
(i) one physical test apart from tasting.
(ii) one chemical test.
(c) Draw a labelled sketch to illustrate the separation of a mixture by sublimation.
(ii) Give two examples of substances that are sublime.
(d)(i) Mention one salt which produces brown fumes on being heated strongly
(ii) What is the action of the brown fumes mentioned in (i) above on litmus.
(iii) Give one reason why it is not advisable to collect nitrogen by displacement of air [N – 14].
All your burette readings (initial and final), as well as the size of your pipette, must be recorded but no account of experimental procedure is required. All calculations must be done in your answer book.
A is a solution containing 14.0gdm\(^{-3}\) of potassium hydrogen tetraoxosulphate (VI). B is a solution of sodium hydroxide.
(a) Put A into the burette and titrate with 20.0cm\(^{-3}\) or 25.0 cm\(^{-3}\) portion of B using methyl orange, as Indicator. Record the volume of your pipette. Tabulate your burette readings and calculate the average volume of A used.
(b) From your results and the information provided, calculate the:
(i) concentration of A in mol dm\(^{3}\)
(ii) concentration of B in g dm\(^3\)
(iii) volume of A (in dm\(^{-3}\)) that would produce one mole of Sodium tetraoxosulphate (VI) in solution. The equation for the reaction is:
2KHSO\(_{4(aq)}\) + 2NaOH\(_{(aq}\) \(\to\) K\(_2\)SO\(_{4(aq)}\) + NaSO\(_{4(aq)}\) + 2H\(_2\)O\(_{(l)}\) [H = 1; O = 16, Na = 23, KHSO\(_4\) = 136gmol\(^{-2}\)]
Credit will be given for strict adherence to instructions, for observations precisely recorded, and for accurate inferences. All tests, observations, and inferences must be clearly entered in your answer book, In ink, a the time they are made.
C is a mixture of two simple salts. Carry out the following exercises on C. Record your observations and identify any gases evolved. State the conclusion you draw from the result of each test.
(a) Add about 10cm\(^3\) of distilled water to all of C in a boiling tube. Shake the mixture and filter: Keep both the filtrate and the residue.
(b) Divide the filtrate into two portions.
(i) To the first portion, add about 2cm\(^3\) of barium chloride solution, followed by dilute hydrochloric acid in excess. Warm the mixture and identify any gas evolved.
(ii) To the second portion, add few drops of acidified potassium tetraoxomanganate (VIl) solution and shake.
(C) Put the residue in a test tube and add about 3cm\(^3\) of dilute hydrochloric acid Warm gently and identify any gas evolved. Keep the mixture.
(d) Divide the clear solution from (c) above into two portions
(i) To the first portion, add sodium hydroxide solution in drops and then in excess.
(ii) To the second, add aqueous ammonia in drops and then in excess.
(a) A soluble chloride X reacted with a liquid Y on heating, to give gas Z which turned moist blue litmus paper red and fumed in moist air.
(i) Identity Y and Z
(ii) Give one chemical test to confirm that X is a chloride
(b)(i) State one laboratory use of calcium chloride.
(ii) Name one laboratory technique suitable for separating a mixture of iron filings and ammonium chloride without applying heat.
(iii) State the action of solutions of the following salts on litmus respectively: K\(_2\)CO\(_3\); NaNO\(_3\), AICl\(_3\), (NH\(_4\))\(_2\)SO\(_4\).
All your burette readings (initial and final), as well as the size of your pipette, must be recorded but on no account of experimental procedure is required. All calculations must be done in your answer book.
(a) Put A into the burette and titrate it against 20.0 cm\(^3\) or 25.0 cm\(^3\) portion of B using methyl orange as indicator. Record the volume of your pipette. Tabulate your burette readings and calculate the average volume of A used. The equation for the reaction is 2NaOH\(_{(aq)}\) + H\(_2\)X\(_{(aq)}\) \(\to\) 2H\(_2\)O\(_{(l)}\)
(b) From your results and the information provided, calculate the;
(i) Concentration of solution B in mol dm\(^{-3}\)
(ii) concentration of solution A in mol dm\(^{-3}\)
(iii) molar mass of the acid H\(_2\)X. [H = 1, O = 16, Na = 23]
Credit will be given for strict adherence to instructions, for observations precisely recorded and for accurate inferences. All tests observations and inferences must be clearly entered in your answer book. in ink, at the time they are made.
C is a mixture of two inorganic compounds. Carry out the following exercises on C. Record your observations and identify any gases evolved. State the conclusion you draw from the result of each test.
(a) put all of C into a beaker and add about 10cm\(^3\) of distilled water. Stir thoroughly and filter. Keep both the residue and the filtrate
(b) Divide the filtrate into three portions.
(i) To the first portion, add sodium hydroxide solution in drops until ít is in excess.
(ii) To the second portion, add aqueous ammonia in drops until it is in excess.
(iii) To the third portion, add about 2cm\(^3\) of barium chloride solution, followed dilute hydrochloric acid in excess.
(c) Put the residue in a test tube and add about 2cm\(^3\) of dilute tetraoxosulphate (VI) acid. Shake the mixture and warm.
(i) Add aqueous ammonia in drops to the mixture from (c) (i) above until it is in excess.
(a) List two gases in each case which;
(i) can be used to demonstrate the fountain experiment;
(ii) decolourize acidified potassium tetraoxomanganate (VII).
(b) State briefly how you would distinguish between
(i) crystals of PbCO\(_3\) and Pb(NO\(_3\)) using heat;
(ii) solutions of NH\(_4\)CI and NaCl using litmus paper.
(c) Mention two changes that would be observed on adding moderately concentrated hydrochloric acid to iron filings
All your burette readings (initial and final), as well as the size of your pipette, must be recorded but on no account of experimental procedure is required. All calculations must be done in your answer book.
A is solution of trioxonitrate (V) acid, B is a solution containing 6.90 g of potassium trioxocarbonate (IV) per dm\(^3\)
(a) Put A into the buret and titrate it against 20.0 cm\(^3\) or 25.0 cm\(^3\) portions of B using methy orange or screened methyl orange as indicater. Record the volume of your pipette. Tabulate your burette readings and calculate the average volume A used. The equation for the reaction is K\(_2\)CO\(_{3(aq)}\) + 2HNO\(_{3(aq)}\) \(\to\) 2KNO\(_{3(aq)}\) + CO\(_{2(g)}\) + H\(_2\)O\(_{(l)}\)
(b) From your results and the information provided calculate;
(i) concentration of solution B in mol dm\(^{-3}\)
(ii) number of potassium ions in 1.00 dm\(^3\) of B [C = 12.0, O = 16.0, K = 39.0, Avogadro constant = 6.02 x 10\(^{23}\) mol \(^{-1}\)]
Credit will be given for strict adherence to instructions, for observations precisely recorded and for accurate inferences. All tests observations and inferences must be clearly entered in your answer book. in ink, at the time they are made.
C is a mixture of two simple salts. Carry out the following exercises on C. Record your observations and identify any gases evolved. Sate the conclusion you draw from the result of each test.
(a) Put all of C into a beaker of boiling tube and add about 10cm\(^3\) of distilled water. Stir well and filter. Keep the residue and keep the residue and the filtrate. Test the filtrate with litmus
(b) Add about 1 cm\(^3\) of dilute hydrochloric acid to the residue in a test tube and warm gently Divide the reaction mixture into two portions.
(c)(i) To the first portion from (b) add saturated sodium trioxocarbonate (V) solution in excess.
(d) To about 2cm\(^3\) of the filtrate from (a) add a few drops of barium chloride solution followed by excess dilute hydrochloric acid.
(a) Name one laboratory equipment used for
(i) keeping salts dry:
(ii) converting vapour to liquid during distillation
(ii) bubbling a gas into a liquid
(b) (i) What technique would you use to purify a sample of sodium chloride contaminated with ammonium chloride?
(ii) Given sodium hydroxide solution, outline the procedure you would use to determine whether or not all the ammonium chloride in (b)(i) above had been removed.
(c) State what is observed on carrying out each of the following exercises.
(i) Adding few drops of methyl orange indicator to lime juice:
(ii) Adding few drops of concentrated HNO\(_3\) to acidified FeSO\(_4\) solution
(iii) Exposing a fresh precipitate of silver chloride to sunlight for 30 minutes
(iv) Adding zinc dust to dilute CuCl\(_2\) solution;
(v) Adding dilute H\(_2\)SO\(_4\), to Pb(NO\(_3\))\(_2\) solution