Aldehyde example cho - Study guides, Class notes & Summaries

AQA A-level CHEMISTRY 7405/1 Paper 1 Inorganic and Physical Chemistry Mark scheme June 2021 Version: 1.0 Final  the cyanide ion or CN– when the reagent should be potassium cyanide or KCN;  the hydroxide ion or OH– when the reagent should be sodium hydroxide or NaOH;  the Ag(NH ) + ion when the reagent should be Tollens’ reagent (or ammoniacal silver nitrate). In this example, no credit is given for the ion, but credit could be given for a correct observation following on f...

For example, in a question requiring 2 answers for 2 marks: Correct answers Incorrect answers (ie incorrect rather than neutral) Mark (2) Comment 1 0 1 1 1 1 They have not exceeded the maximum number of responses so there is no penalty. 1 2 0 They have exceeded the maximum number of responses so the extra incorrect response cancels the correct one. 2 0 2 2 1 1 2 2 0 3 0 2 The maximum mark is 2 3 1 1 The incorrect response cancels out one of the two correct responses that ...

  Chemistry - Correct Answers: Science dealing with the molecular and atomic structure of matter and of the composition of substances--their formation, decomposition, and the various transformations that they may undergo Inorganic Chemistry - Correct Answers: The study of compounds usually containing elements other than carbon Organic Chemistry - Correct Answers: The study of certain carbon compounds Biochemistry - Correct Answers: - Chemistry of living things - The study of compoun...

Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation events which all associates participate in and is the scheme which was used by them in this examination. The standardisation process ensures that the mark scheme covers the students‟ responses to questions and that every associate understands and applies it in the same correct way. ...

AQA A-LEVEL CHEMISTRY 7405/2 PAPER 2 MARK SCHEME A-level CHEMISTRY 7405/2 Paper 2 Organic and Physical Chemistry Mark scheme Version: 1.0 Final *206A7405/2/MS* Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation events which all associates...

AQA A-LEVEL CHEMISTRY 7405/2 PAPER 2 MARK SCHEME A-level CHEMISTRY 7405/2 Paper 2 Organic and Physical Chemistry Mark scheme June 2020 Version: 1.0 Final *206A7405/2/MS* Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation events which all a...

AQA A-LEVEL CHEMISTRY 7405/2 PAPER 2 MARK SCHEME A-level CHEMISTRY 7405/2 Paper 2 Organic and Physical Chemistry Mark scheme Version: 1.0 Final *6A7405/2/MS* Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation events which all associates p...

AC-HPAT Chemistry Questions With Complete Solutions. double-displacement reaction A double displacement reaction, also known as a double replacement reaction or metathesis, is a type of chemical reaction where two compounds react, and the positive ions (cation) and the negative ions (anion) of the two reactants switch places, forming two new compounds or products Precipitate precipitate is an insoluble solid that emerges from a liquid solution. The emergence of the insoluble solid from sol...

double-displacement reaction - AnswersA double displacement reaction, also known as a double replacement reaction or metathesis, is a type of chemical reaction where two compounds react, and the positive ions (cation) and the negative ions (anion) of the two reactants switch places, forming two new compounds or products Precipitate - Answersprecipitate is an insoluble solid that emerges from a liquid solution. The emergence of the insoluble solid from solution is called precipitation. Often t...

3.2 Marking procedure for calculations Full marks should be awarded for a correct numerical answer, without any working shown, unless the question states ‘Show your working’ or ‘justify your answer’. In thiscase, the mark scheme will clearly indicate what is required to gain full credit. If an answer to a calculation is incorrect and working is shown, process mark(s) can usually be gained by correct substitution / working and this is shown in the ‘Comments’column or by each stage o...