FREE CHEMISTRY AND STUDY GAMES ABOUT AQA A1

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FREE CHEMISTRY AND STUDY GAMES ABOUT AQA A1

GROUP 2 AND 7 EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -35 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: Explain why there is no reaction between Sodium Chloride and Bromine

Answer:

Because Chlorine is a stronger oxidising agent than bromine and will not get displaced, REDUCED.KEYWORDS in Year 12: do not say "more reactive"=describe which is more oxidising; describe which gets REDUCED (ie not merely "displaced") Question 2: Describe and explain the trend for the melting point of group 2 metals down the group

Answer:

As you go down, mp decreases as the delocalised e- from the outer shell are further away from nucleus, so less attraction between delocalised e- and positive ions=weaker metallic bonds Question 3: Explain whybarium hydroxide solution is more alkaline than Magnesium Hydroxide

Answer:

Ba(OH)2 is more soluble than Mg(OH)2 so more Hydroxide ions OH- end up in solution hydroxide ions are alkaline

Question 4: Describe and explain the trend of oxidising power of Halogens down the group

Answer:

As you go down the group, outer shell is further away from the nucleus, any extra e- is less likely to be attracted so Iodine LESS likely to become Iodide and GET REDUCED; oxidising power decreases Question 5: Write the equation between solid sodium Chloride and concentrated sulphuric acid

Answer:

NaCl + H2SO4 ? HCl + NaHSO4; mnemotechnic SHWI and SWOB Question 6: Write the IONIC equation for the reaction between Sodium Bromide and Chlorine

Answer:

2Br- + Cl2? Br2 + 2Cl-; SNAP ions do not show in an ionic equation; Check formulae; balance the equation; check states symbols Question 7: Describe and explain the trend of reactivity of group 2 metals down the group

Answer:

As you go down the group, metals become more reactive; all have 2 e- in outer shell; as you go down, e- are further away from nucleus; more shielding; less attraction; less energy to remove e- ie to react

SCARED

Question 8: Write the equation for the reaction of Magnesium with steam

Answer:

Mg+ H2O ? MgO + H2 Question 9: Why must Barium Chloride or Silver Nitrate be acidified before the tests for SO4-2 or Halide ions?

Answer:

To remove carbonate ions Question 10: Describe the explain the trend in boiling point (bp) of the Hydrogen Halides HX as you go down the group

Answer:

All HX are simple molecular; all has VdW and pd-pd; as you go down the group, elements are less electronegative so pd is weaker so pd-pd is weaker so bp will decrease (note VdW BTEWEEN MOLECULES increases)

Question 11: Describe and explain your observations when solid sodium bromide is placed in concentrated H2SO4

Answer:

steamy fumes of HBr, and brown fumes of Br2; first NaBr + H2SO4 ? HBr + NaHSO4; then, the Br- ions reduce the conc H2SO4 (SWOB); note that SO2 is colourless Question 12: Write the equation for the reaction of aluminium oxide with sulfuric acid

Answer:

Al2O3 + 3 H2SO4 ? Al2(SO4)3 + 3 H2O; check formulae!!!!Question 13: During the test for sulfate ions, you add acidified Barium Chloride. Why should you NOT use sulphuric acid to acidify?

Answer:

Otherwise the sulfate ions from H2SO4 would react with Barium ions and form a precipitate

Question 14: Write the equation between Cl2 and cold water

Answer:

Cl2 + H2O ? HCl + HClO; mnemotechnic ClOCl Question 15: Describe the trend of solubilities of Group 2 hydroxides and group 2 sulfates as you go down teh group

Answer:

As you go down the group, hydroxides become more soluble and sulphates less soluble (HBST=Hydroxide soluble at Bottom and Sulfates at Top) Question 16: Describe the explain the trend in boiling point (bp) of the Halogens as you go down the group

Answer:

All Halogens are X2 formula and are simple covalent; all hav VdW forces BETWEEN MOLECULES; as you go down the group, the number of electrons increases so VdW forces BETWEEN MOLECULES will increase Question 17: Write the equation between Hydrogen Bromide and concentrated sulphuric acid

Answer:

HBr+ H2SO4 ?SO2+ H2O+ Br2 ; mnemotechnic SHWI and SWOB

Question 18: Describe and explain your observations when solid sodium iodide is placed in concentrated H2SO4

Answer:

steamy fumes of HI, and black solid of I2 and rotten egg smell of H2S; first NaI + H2SO4 ? HI + NaHSO4; then, the I- ions reduce the conc H2SO4 (SHWI) ; note that SO2 is colourless

Question 19: Write the equation between Cl2 and sodium hydroxide

Answer:

Cl2 + NaOH ? NaCl + NaClO +H2O; mnemotechnic ClOCl; but you still need to remember H2O!Question 20: Write the simplest IONIC equation for the precipitation of Magnesium Hydroxide

Answer:

Mg+2 + 2 OH- ? Mg(OH)2; Check formula of the precipitate; unswap; the ions go as reactants; balance the equation; check states symbols (precipitate=s) Question 21: Explain why patients eat a barium meal even when Barium ions are toxic

Answer:

because the barium meal is barium sulfate; BaSO4 is insoluble so no Barium ION is dissolved, none will cross the intestine wall and go into blood stream Question 22: Use oxidation numbers to show that the reaction between Calcium and Water is a redox reaction

Answer:

Ca+ 2H2O? Ca(OH)2 + H2; Ca goes from 0 to +2=oxidation and H from +1 to 0=reduction; work out the oxidation state the elements that not combined first ; inside a compound H is ALWAYS +1 ie in H2O, H is NOT +2!!!!Question 23: Explain why Nitric acid must be used to acidify the silver nitrate and not Sulfuric acid or hydrochloric acid?

Answer:

otherwise precipitates of AgCl or Ag2SO4 form Question 24: Write the simplest IONIC equation for the reaction of Barium Chloride with Sodium Sulfate

Answer:

Ba+2 + SO4-2- -->Ba(SO4); FIRST: Barium Sulfate PRECIPITATE is made: treat this as a precipitation reaction; and/or SNAP ions do not show in ionic equation; Check formula precipitate; unswap; ions go as reactants; balance equation; check states symbols