男人资源站-涩涩五月天-加勒比一区二区-欧美丰满少妇-清纯唯美亚洲-蜜臀久久99精品久久久久宅男-1024手机在线观看-a免费在线观看-日韩一区二区三免费高清在线观看-激情欧美一区二区-日韩综合网站-色小说av-夜夜夜操操操-色片在线播放-免费在线观看中文字幕

  • 翰林提供學(xué)術(shù)活動(dòng)、國際課程、科研項(xiàng)目一站式留學(xué)背景提升服務(wù)！
Home » 國際課程 » A-level課程 » Details

Edexcel A Level Chemistry:復(fù)習(xí)筆記1.6.3 Applying Equations

Category: A-level課程, 教材筆記, 福利干貨 Date: 2022年9月9日 上午9:33

Relating Observations to Chemical Equations

 

  • Chemical equations give information about the reaction that is taking place
    • Balanced equations show the number of particles participating in the reaction and the number of products being formed
    • Balanced equations can be used to calculate the number of moles involved in reactions
    • Balanced equations can, also, be used to calculate masses and volumes involved in reactions
    • Ionic equations only show the reacting particles
    • Ionic equations allow you to identify spectator ion

Types of reaction

  • Chemical equations can be used to determine the type of reaction taking place

Displacement reactions

Br2?(aq) + 2KI (aq) → I2?(aq) + 2KBr (aq)

  • ?In this reaction, the more reactive bromine?displaces?the less reactive iodide in potassium iodide
  • This can also be seen in the ionic equation for the reaction

Br2?(aq) + 2I-?(aq) → I2?(aq) + 2Br-?(aq)

Exam Tip

The use of chemical equations can help identify risks and hazards in the reaction and suggest appropriate precautions where necessary

For example, the use of aqueous bromine in the above example should suggest the potential use of a fume cupboard and nitrile gloves because:

  • Bromine liquid is?toxic,?corrosive?and?harmful to the environment
  • Bromine water with a concentration of 0.2 mol dm3?is corrosive
  • With a concentration of between 0.06 mol dm3?and 0.2 mol dm3, bromine water is an?irritant
  • Only below concentrations of 0.06 mol dm3?is bromine water considered a?low hazard

Neutralisation reactions

  • These can be identified by the presence of reactant acids and bases as well as the formation of a?neutral salt solution?and water (and sometimes other compounds such as carbon dioxide)

HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l)

Na2CO3?(aq) + 2HNO3?(aq) → 2NaNO3?(aq) +?H2O (l) + CO2?(g)

  • ?The ionic equations can more clearly demonstrate the neutralisation of an acid and a base:

H+?(aq) + OH-?(aq) → H2O (l)

2H+?(aq) + CO32-?(aq) → H2O (l) + CO2?(g)

Exam Tip

For neutralisation reactions, the main hazards are linked to:

  • The concentration of the acid
  • The type of acid
    • This could mean?strong,? e.g. HCl, or?weak, e.g. CH3COOH
    • This could also mean?monoprotic, e.g. HNO3,?diprotic,?e.g. H2SO4, or?triprotic, e.g. H3PO4
  • The concentration of the base
  • The strength of the base
  • The physical state of the base, e.g. NaOH (s) is arguably considered more corrosive than a high concentration solution of NaOH (aq)

Precipitation reactions

  • These are shown by the reaction of two aqueous solutions to form products which include one solid

BaCl2?(aq) + Na2SO4?(aq) →?BaSO4?(s) + 2NaCl (aq)

  • ?The ionic equation shows the precipitation reactions more clearly as there are no other products considered

Ba2+?(aq) + SO42-?(aq) →?BaSO4?(s)

Exam Tip

A precipitation reaction is a clear example of where consideration for further?practical procedures is most obvious

The formation of a solid product should tell you that any purification of the product should include filtering or decanting as a minimum

 

轉(zhuǎn)載自savemyexams

以上就是關(guān)于【Edexcel A Level Chemistry:復(fù)習(xí)筆記1.6.3 Applying Equations】的解答，如需了解學(xué)校/賽事/課程動(dòng)態(tài)，可至翰林教育官網(wǎng)獲取更多信息。

往期文章閱讀推薦：

全網(wǎng)破防！ALevel CIE數(shù)學(xué)M1疑似錯(cuò)題？經(jīng)濟(jì)P2難度飆升？5月6日大考考情分析必看！

A-Level CIE就大規(guī)模泄題發(fā)布最嚴(yán)處罰！哪些考生必須重考？你的成績怎么辦？

? 2026. All Rights Reserved. 滬ICP備2023009024號(hào)-1

國際競賽 國際競賽
了解背提項(xiàng)目
國際課程 國際課程
國際課程
商務(wù)合作 商務(wù)合作
商務(wù)合作
課程試聽 課程試聽