EXPERIMENT QUESTIONS

1. (a) TEST FOR REDUCING SUGAR:

FOOD SOURCE: Glucose (monosaccharide)

CHEMICAL USED: Benedict’s solution (blue)

HEAT REQUIRED: Yes (thermostatically controlled water bath)

+ RESULT: Colour change BLUE to BRICK RED

- RESULT: No colour change (stays blue)

CONTROL: Water + Benedict’s (non-reducing sugar)

PURPOSE OF CONTROL: Acts as a comparison

1. (b) TEST FOR STARCH:

FOOD SOURCE: Potato/ Bread

CHEMICAL USED: Iodine (red/yellow), using a dropper due to small volume needed

HEAT REQUIRED: No

+ RESULT: Colour change RED/ YELLOW to BLUE/BLACK

- RESULT: No colour change (stays red/yellow)

CONTROL: Water and Iodine

1. (c) TEST FOR... (More)

Light

• Refraction is the bending of light as it goes from one medium to another.
  
• Laws of Refraction: (1) Incident ray, refracted ray & normal are on the same plane. (2) Sine I/Sine R is constant.
• Refractive Index: Sine I/Sine R = 1/Sin C = Real depth/Apparent depth = c1/c2
• Critical Angle: The angle whose angle of incidence is 90 when light goes from a denser to a rarer medium.
• Total Internal Reflection: When light travelling from a denser to a rarer medium strikes the second medium with an angle of incidence greater than the critical angle, it is reflected... (More)

Desdemona assures Cassio that she will do everything possible to regain favor with Othello. He soon enters, and Cassio departs as he is too nervous to argue his case suitably. Iago declares that Cassio would not act akin to one who is guilty, while Desdemona once more argues Cassio’s case, which causes Othello to agree to meet with him at an unspecified time. Desdemona criticizes such procrastination but he assures her he will do anything she wishes, and that he wishes to be left alone. Left alone, Iago suggests that Cassio and Desdemona had an affair while Cassio acted as... (More)