Innostan

A large difference between experimental and calculated lattice enthalpy values are due to... - correct answerrelatively large degrees of covalent bonding. positive ions can be said to polarise negative ions, if they cause distortion of the charge cloud. They can pull electrons to one side of the ion. As temperature rises what happens to the rate constant? - correct answerAs temperature rises, the rate constant gets larger, so the rate is faster As the activation energy rises what happen...

Acid-base titration - correct answer- pipette 25cm³ acid and add indicatir, place beaker on a magnetic stirrer and place magnet in the beaker, fill burette with base - rinse electrode with distilled water as readings may have changed over time, dip it into the acid in the beaker, recording pH -switch on stirrer and ensure magnet doesnt strike the electrode. - add 5cm³ base and take readings of pH and indicator - continue adding base taking 5cm³ readings each time then 1cm³ around end poi...

(some are partly done) qualitative tests for ions and organic functional groups, a b c f h, k, volatges. - correct answer Acid-Base Titration - correct answerrinse equipment (burette with acid, pipette with alkali, conical flask with distilled water) •pipette 25 cm3 of alkali into conical flask •touch surface of alkali with pipette ( to ensure correct amount is added) •adds acid solution from burette •make sure the jet space in the burette is filled with acid •add a few dr...

Carry out simple test-tube reactions to identify anions. 7 - halide ions- add small volume of nitric acid to solution followed by silver nitrate solution. different coloured ppt shows different halide ions, add excess dilute ammonia solution followed by conc ammonia solution to confirm halide ions. group 7 solid salts- add conc sulphuric acid to potassium halide. record observations, KCl- white misty fumes, KBr- orange fumes, KI- purple fumes and purple/black solid. test gas with damp blue litm...

aqa a level question and answer

Amino Acid - correct answerOnly different and specific in the R group. The R group represents a side chain from the central 'alpha' carbon and can be anything from a simple hydrogen atom to a more complex ring structure. The R group defines the amino acid. Glycine is the only amino acid that does not contain carbon. 20 amino acids make up all living things. Amylopectin (75%) - correct answer- Long, branched chain of alpha glucose -Side branches allow the enzymes to break down the mol...

3.1.5.2 - correct answerDNA REPLICATION a change in pH alters the charges on the amino acids that make up the active site of the enzyme, as a result ... - correct answerthe substrate cant become attached to the active site, meaning the enzyme-substrate complex cannot be formed A functional protein may contain ... - correct answerOne or more polypeptides a proteins shape is very specific to its function, change it and ... - correct answerit will function less well or differently a sig...

100 stacked discs of thylakoids - correct answerwhat is the grana? 95 = separate polynucleotide strands, 50 = mixture cooled so primers may anneal to strand, 72 = heated so DNA polymerase can join complimentary bases - correct answerWhat temperatures are used in heat treatment and what do they do? A protein that controls the rate of transcription - correct answerWhat is a transcription factor? acetyl coenzyme A combines with oxaloacetate to form citrate which is decarboxylated and dehyd...

A farmer thinks a potato crop is infected with potato virus. The farmer obtains a monoclonal antibody kit for PVY. To make the monoclonal antibodies a scientist first isolates the PVY protein from the virus. Describe how the scientist would use the protein to produce the PVY monoclonal antibody. (4 marks) - correct answer1. Inject the protein into a mouse 2. Combine lymphocytes with tumour cells to form hybridoma cells 3. Find a hybridoma that produces a monoclonal antibody specific to PVY ...

A cycle is a biological pathway or process in which the end product of one cycle becomes the starting point for the next. Write an essay about cycles in biology - correct answer1) Nitrogen cycle 2) Enzyme action 3) Synthesis of ATP from ADP 4) Light-independent reaction 5) The Krebs cycle 6) The mechanism of breathing 7) The cardiac cycle 8) The cell cycle/mitosis 9) meiosis 10) Muscle contraction Cells and organisms carry out exchanges with their external environment to maintain ...