Biscuit experiment

Question 1

Apparatus

Answer 1

boiling tube
stand, boss, clamp
tongs
bunsen burner and mat

Question 2

Apparatus 2

Answer 2

3 biscuit types
Thermometer
10cm3 measuring cylinder
Access to electronic balance

Question 3

Method

Answer 3

1. measuring cylinder pour 10cm3 into a boiling tube
2. assemble apparatus
3. take temp of water and record
4. measure mass of bisc
5. use tongs, set biscuit alight and hold under the tube of water.
6. once biscuit has burnt out, take temp of water and record in table

Question 4

What is the independent variable of this experiment

Answer 4

type of biscuit

Question 5

what is the dependent variable

Answer 5

temperature change in water

Question 6

what is the control variable

Answer 6

volume of water, same flame on bunsen, distance of biscuit from water

Question 7

how to work out the energy content in j/g

Answer 7

Difference in temperature (oC) x mass of water (g) x 4.2 (J/ oC) divided by Mass of food(g)

Question 8

valid

Answer 8

true measure

not all energy went into the water, some into atmosphere, glass, wasted

Question 9

reliable

Answer 9

repeat and identify anomalies

did not repeat, so not reliable

Question 10

accurate

Answer 10

a for apparatus
improve by using calorimeter
using second clamp stand to keep the distance of the flame from the water the same

Question 11

how does a calorimeter work

Answer 11

by using an electrically powered ignition coil to ignite the food in an atmosphere of pure oxygen

Question 12

why is this an improvement

Answer 12

all the energy from the biscuit goes into the water
insulated so heat cannot go into atmosphere
burning in oxygen leads to pure combustion
no energy lost when moving the food sample