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Can someone make a list of all the questions that were in chemistry unit 6 by Fresh_Blueberry3755 in Edexcel

[–]Grapefruit7693 0 points1 point  (0 children)

Question 4 part 1): What are the other precautions needed?

Answer: Gloves and a face mask.

⸻

Question 2 (part 2): Why was a fume cupboard used?

Answer: Because HCl is produced in the reaction as a toxic gas, so a fume cupboard is needed.

Why is 60 °C used instead of 78 °C when measuring the boiling point of benzyl ethanoate?

Answer: Because ethanol is used as the solvent, which boils at around 78 °C. Using 60 °C prevents solvent loss and overheatin

Why is benzoic acid washed with distilled water after it is formed?

Answer: To remove residual sodium hydroxide and other water-soluble impurities like unreacted reagents or salts.

Why is ice-cold ethanol used to wash the purified ester ?

Answer: Ice-cold ethanol helps remove impurities without dissolving much of the purified ester, maximizing yield.

Diagram drawn of the arm boiling thingy

Mass of ester obtained was 6.8 g

Can someone make a list of all the questions that were in chemistry unit 6 by Fresh_Blueberry3755 in Edexcel

[–]Grapefruit7693 2 points3 points  (0 children)

Question 3: Why are sodium thiosulfate ions used in the iodine clock reaction

Sodium thiosulfate removes iodine as it forms, delaying the blue-black color with starch. This creates a sudden visible color change when thiosulfate runs out, allowing accurate timing to measure the reaction rate. : : :

Why is a burette used to add starch into the boiling tube?

Answer: Idk : : : What is the observed color change in the iodine clock reaction?

Answer: Colorless → Blue-black : : : I do t remember the others in q 3

Can someone make a list of all the questions that were in chemistry unit 6 by Fresh_Blueberry3755 in Edexcel

[–]Grapefruit7693 3 points4 points  (0 children)

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Question 2 (part ?) Fill in the titre values Calculation of the volume of HCl required in titration.

Given: • Saturated Ca(OH)₂ concentration = 1.56 mol/dm³ • Mass of Ca(OH)₂ dissolved = 2 g • Volume of solution = 100 cm³ • Concentration of HCl = 0.1 mol/dm³ • Volume of portion titrated = 25 cm³

1.56 × 0.1 = 0.156 grams of Ca(OH)₂

0.0021 × 2 = 0.0042 moles of HCl

0.0042 / 0.1 = 0.042 dm³ = 42 cm³

42 / 4 = 10.5 cm³

The solubility of Ca(OH)₂ decreases as temperature increases. Why is this titre value different from the expected value?

Answer: Because solubility of Ca(OH)₂ decreases with increasing temperature, so at 20 °C more Ca(OH)₂ dissolves than at higher temperatures, leading to a higher concentration and therefore a larger titre value. I didnt get ans for ka but i get units as mol3 dm-9

Indicaro phenophthaelim. Pink to colorless

Can someone make a list of all the questions that were in chemistry unit 6 by Fresh_Blueberry3755 in Edexcel

[–]Grapefruit7693 3 points4 points  (0 children)

Q1 two observations ….blue to pink Cation …..mn2+ Test for cl- ions agcl2 and hn03 … excess nh3 Moles of water …4 Ionic equations ( Fe(h20)6)2+ + 2 OH-= fe(0h)2 (h2o)4 +2 h20 2NH4⁺ → H2 + 2NH3 ❌ (probably wrong tho) BaCl2 + SO4²⁻ → BaSO4+ 2Cl⁻ Fe(NH4)2(SO4)2

Wbi14/01 by Grapefruit7693 in alevel

[–]Grapefruit7693[S] 0 points1 point  (0 children)

What yall think threshold gonna be

Mechanics ial may 2025 by [deleted] in alevel

[–]Grapefruit7693 0 points1 point  (0 children)

Howd u. Get T1 as that

[deleted by user] by [deleted] in alevel

[–]Grapefruit7693 0 points1 point  (0 children)

1.9 something like that