1) Give formulae for these substancesA) hydrochloric acid HClB) sulphuric acid H SO4 2 C) nitric acid HNO3D) ethanoic acid CH3COOHE) Sodium hydroxide NaOH F) Potassium hydroxide KOHG) Barium hydroxide Ba(OH)2
2) Give examples of• A) strong acids HCl, H2SO4, HNO3• B) Weak acids CH3COOH, ethanoic acid• C) Strong alkali NaOH, KOH, Ba(OH)2• C) Weak alkali NH4OH,
3) State 4 chemical properties of acids• A) reacts with metals to form SALT + HYDROGEN GAS• B) reacts with oxide metals to form SALT + WATER• C) reacts with alkali to form SALT + WATER• D) reacts with carbonate metals to form SALT + CARBON DIOXIDE + WATER
Fill in the table below Beaker A Beaker Ba) Add blue dry BLUE LITMUS PAPER NOlitmus paper CHANGE TO RED CHANGEb) Add EFFERVESCENCE OCCUR.magnesium COLOURLESS GAS RELEASE NOribbon WHICH GIVES ‘POP’ SOUND CHANGE WHEN TESTED WITH BURNING WOODEN SPLINTERc) Add marble EFFERVESCENCE OCCUR.chips NO COLOURLESS GAS CHANGE RELEASE WHICH TURN LIME WATER CLOUDY
• Which beaker shows acidic property? Why? Beaker A because hydrogen chloride ionised in water to form H+ ions. Therefore it shows the acidic properties• What is the role of water in this experiment?To ionise hydrogen chloride into H+ ions and show its acidic properties
Write chemical equations for reactions in beaker A)• i) with magnesium ribbon 2 HCl + Mg → MgCl2 + H 2• ii) with marble chips2 HCl + CaCO3 → CaCl2 + CO2 + H 2O
Does solution formed in beaker A conduct electricity? Explain your answerYes because solution A containmobile/free moving ion.
5) Table below shows some solutions with different pHsubstan Solution Solution Solution Solution Solutionce A B C D EpH 2 5 7 8 13values
Which solution isb)A strong acid? Solution Ac)A strong alkali? Solution Ed)Neutral solution? Solution Ce)Weak acid? Solution Bf)Weak alkali? Solution Dg)Has high concentration of hydrogenions? Solution Ah)Has low concentration of hydroxideions? Solution E
6) Calculations on concentrations• 4 grams of sodium hydroxide is dissolved in 100 cm3 of water• Calculate concentration of the solution formed in: A) g/dm3
6) Calculate concentration of the solution formed inB) mol/dm3 1000 cm3 = 1 dm3
8) Calculations on formula, mole = MV/1000 and mole = mass/molar mass• How many moles of NaOH contained in 100 cm3 of 2.0 mol dm-3 NaOH solution ?
What is the mass of NaOH needed to make asolution of 100 cm3 NaOH concentration 0.2moldm-3? ( given RAM Na, 23: O,16: H,1)
What is the concentration of 0.5 moles HCl in avolume of 100 cm3 solution ?
7) Calculations on titration• 100 cm3 of 0.2 mol /dm3 sulphuric acid neutralise exactly 100 cm3 of sodium hydroxide solutionCalculate the concentration of the sodium hydroxide solution [H+] Ma Va = [OH] Mb Vb 2x 0.2 x 100 = 1 x Mb x 100 So Mb = 2 x 0.2 x 100 /100 = 0.4 mol dm-3
8) Calculations on dilution• 90 cm3 of distilled water is added to a volume of 10 cm3 of nitric acid with a concentration of 2.0 mol /dm3. What is the concentration of acid after the dilution? M 1V1 = M 2V22(10) = M 2 (100) −3∴ M 2 = 0.2moldm