Elements, Compounds And Mixtures
Muhtasari
Look around any kitchen and you will find elements (the copper in wiring), compounds (the sodium chloride in your salt shaker) and mixtures (the air you breathe). Telling them apart, and separating mixtures into their components, is one of the oldest skills in chemistry.
In this lesson you will learn the definitions that distinguish elements, compounds and mixtures, explore how melting-point data reveals purity, and master five separation techniques that Edexcel tests regularly: distillation, fractional distillation, filtration, crystallisation and paper chromatography.
Malengo
- understand how to classify a substance as an element, compound or mixture
- understand that a pure substance has a fixed melting and boiling point, but that a mixture may melt or boil over a range of temperatures
- describe these experimental techniques for the separation of mixtures: - simple distillation - fractional distillation - filtration - crystallisation - paper chromatography.
- understand how a chromatogram provides information about the composition of a mixture
- understand how to use the calculation of Rf values to identify the components of a mixture
- practical: investigate paper chromatography using inks/food colourings
Maelezo ya Somo
Inapatikana kwenye programu ya Green Bridge
Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.
Tathmini ya Somo
Hongera kwa kukamilisha somo la Elements, Compounds And Mixtures. Sasa kwa kuwa umechunguza dhana na mawazo muhimu, ni wakati wa kuweka ujuzi wako kwa mtihani. Sehemu hii inatoa mazoezi mbalimbali maswali yaliyoundwa ili kuimarisha uelewaji wako na kukusaidia kupima ufahamu wako wa nyenzo.
Utakutana na mchanganyiko wa aina mbalimbali za maswali, ikiwemo maswali ya kuchagua jibu sahihi, maswali ya majibu mafupi, na maswali ya insha. Kila swali limebuniwa kwa umakini ili kupima vipengele tofauti vya maarifa yako na ujuzi wa kufikiri kwa makini.
Tumia sehemu hii ya tathmini kama fursa ya kuimarisha uelewa wako wa mada na kubaini maeneo yoyote ambapo unaweza kuhitaji kusoma zaidi. Usikatishwe tamaa na changamoto zozote utakazokutana nazo; badala yake, zitazame kama fursa za kukua na kuboresha.
- Which of the following is a compound? A) Nitrogen gas (N2) B) Bronze C) Water (H2O) D) Air Answer: C
- A pure substance can be identified because it: A) Is colourless B) Has a sharp, fixed melting point C) Dissolves in water D) Cannot be filtered Answer: B
- Which separation technique would you use to obtain pure water from salt water? A) Filtration B) Crystallisation C) Simple distillation D) Paper chromatography Answer: C
- In paper chromatography, what is the mobile phase? A) The pencil line B) The paper C) The solvent D) The spots Answer: C
- An Rf value of 0.75 means the substance has travelled: A) 75% of the distance to the solvent front B) 75% of the total paper length C) 25% of the distance to the solvent front D) Three quarters of the way to the top of the paper Answer: A
Inapatikana kwenye programu ya Green Bridge
Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.
Inapatikana kwenye programu ya Green Bridge
Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.
Vitabu Vinavyopendekezwa
Fanya Mazoezi ya Maswali ya Majaribio
Ungependa kufanya mazoezi ya maswali ya majaribio kuhusu Elements, Compounds And Mixtures? Pakua programu ya Green Bridge CBT ili kupata maswali ya majaribio na tathmini kamili za mazoezi kuhusu mada hii.
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