Ok so the thing is chembridge and carboxyl have both launched their recorded batches. Now I know both teachers are good, but I'm confused on which teacher to pick for AS LEVEL. though cArboxyls recorded batch is more expensive than sir faizans. Any suggestions.
Length 7.0
Meters: 0.350 (had to write to 3.sf)
1.19 tha shyd time
T is not propoetionalt I L since the value of constant K is not same, and not within the limits of experimental accuracy
9.6
9.4
Just show proof
Yes they are equal
Use of fidicial aid/ use of micrometer to measure diameter of Bob and add half of diameter to length of thread/ use of set square to keep rule vertical. Repeating the experiment is not accepted.
Time/seconds
T°C
12
8
3.0
2.0
Beaker Q since the rate of cooling is lower, and temperature change asw and just quote values from the table.
Remove the lid from beaker Q
Safety gloves and googles to avoid hot spills
/use long handed tool to handle beaker.
Resistor in series
Volt meter in parrallel
Current reading 0.33A
Gradient 2.0-2.2 (could be written in minus, tho Ms usually says positive)
Triangle method on graph clearly shown
Resistance 2.0
Voltmeter in parallel with the battery
Terminals must not touch since it may lead to short circuit or electurication or explosion
Exp
Apparatus MEAUSRING cylinder, ruler and electronic stop watch.
Undepdant variable type of fan setting/speed of fan/rpm
Dependant variable; rate of cooling
Method; change in temperature over a fixed period of time, and repeat experiment for the same setting of fan at least 2 times, and take average value of rate of cooling by T/s (where s is in seconds)
Repeat experiment using same type of beaker, same volume of hot water, and same intial temp (there were other variables to control asw, you needed to write anyone)
Table with column headings
Bar chart of type of fan setting on x axis with rate of cooling on y axis
Or graph of rpm against rate of cooling
Take at least 5 sets of readings.
Guys, I'm planning to take As chemistry from Carboxyl.
To those who have studied from him in o levels, or their siblings have studied from him in a levels. Kindly tell me how is he
Guys just came to my mind, pehlay question me were they adding vitamin c to dcpip or dcpip to vitamin c?
Table:
Percentage concentration of vitamin c
Drops of dcpip added until solution turns colourless. (Smth like this)
Concentration:
Any number between 0.25 and 0.5
Reason: number of drops required greater than 0.25% solution but less than 0.5%
Source of error:
Drops size vary/ endpoint hard to exactly identify therefore an extra drop can be added.
Adding vitamin c to distilled water/ adding dcpip to distilled water.
Graph
Y axis label
X axis label
Ruled straight line
Value; 0.75 (varies a bit for everyone)
Repeat the experiment using intermediate values b/w 0.70 and 0.80, and plot another graph.
Why exp better;
Calculates actual mean volume, which helps to reduce effect of human error and reduces uncertainty. Similarly, rather than estimating a graph has been plotted for the results, helping to obtain a precise value.
Not sure if this correct I heard it from someone else (clean apparatus)
Y as it's more concentrated.
Exp:
Test tube with fixed volume of distilled water and vitaminc c.
Using a graduated pipette suck a fixed volume of dcpip or a syringe. Measure the temperature.
Add the dcpip to the test tube, and note the volume used until decolorization.
Set up the experiment again, this time add the dcpip to a test tube. Keep the test tube in a test tube rack, and heat in a thermostatically controlled water bath at 30°C. Submerge a thermometer, and allow it to expand. Read at eye level to get an accurate reading, avoiding parrlayx error. Then, take out the test tube using forceps, and suck the liquid again. Add the dcpip to the same volume of vitamin c (and same concentration) Note the volume used.
Repeat this same set up at temperatures of 40°C, 50°C, 60°C and 70°C. Heating should be done for the same duration, timed using an electronic stop watch, for 30 minutes.
Wear gloves and safety googles, to avoid hot spills and hand burns.
Eventually note the temperature at which lemon juice no longer turns colourless, and repeat the experiment again at temperatures below this interval. Plot a graph of your results of temperature on the x axis and volume of dcpip needed to decolurize on the y axis.
Temperature is in the independent variable.
Differences and similarity
Rectangular (regular) for onion epidermis and irregular (slightly oval) for cheek cells.
Onion epidermis has an outer boundary (cell wall)
Both contain one black dot (nucleus)
These answers are not 100% accurate, but made from various sources.