Hsc Marathon 2009 - Chemistry (1 Viewer)

[dunny12]

O wow. I literally just finished writing up a summary for this dot point.

Domestic Smoke Alarms:
Simple Domestic Smoke Alarms contain a small source of alpha particles(usually Am-241). These particles ionize in air, the ions are collected by an electrode and the resulting electrical current is measured. When smoke(small solid particles) is present in the air, it prevents ions reaching the electrode causing a reduction in the electrical current which triggers an alarm.

Describe what is meant by a conjugate acid/base pair.

 

[rarefish]

An acid is one that releases a proton, by the Bronsted and Lowry definition. Thus it turns to its conjugate base. A base receives a proton from the acid and becomes its conjugate acid. That is a conjugate acid/base pair.

Question
Describe the difference between a complete and incomplete combustion. With use of equations

 

[Ryuu-jin-jakka]

Describe the difference between a complete and incomplete combustion. With use of equations

A complete combustion is when sufficient oxygen reaches the gas e.g.(methene) therefore producing carbon dioxide & Water
CH4(g) + 2O2(g) --> CO2(g) + 2H2O(g)

A incomplete combustion is when there isn't enough of oxygen (air hole is partly open) to react with the gas therefore carbon monoxide and water are produced CH4(g) + O2(g) --> C(s) + 2H2O(g)


Question
Describe the composition and layered structure of the atmosphere (straight from dot point)

 

[shady145]

A complete combustion is when sufficient oxygen reaches the gas e.g.(methene) therefore producing carbon dioxide & Water
CH4(g) + 2O2(g) --> CO2(g) + 2H2O(g)

A incomplete combustion is when there isn't enough of oxygen (air hole is partly open) to react with the gas therefore carbon monoxide and water are produced CH4(g) + O2(g) --> C(s) + 2H2O(g)


Question
Describe the composition and layered structure of the atmosphere (straight from dot point)

troposphere, stratosphere, ionosphere
79% N 20% O 1% Ar
lol, short answerd to the max

 

[Shizzlester]

troposphere, stratosphere, ionosphere
79% N 20% O 1% Ar
lol, short answerd to the max

Mesosphere and thermosphere?

 

[Ryuu-jin-jakka]

Question
Describe the composition and layered structure of the atmosphere (straight from dot point)

Okie, nm that question... i've already done it


Question
Describe each components in an AAS process

 

[eoklm11]

Okie, nm that question... i've already done it


Question
Describe each components in an AAS process

Light source= send out light in same frequency as element to be tested for

Flame= vaporizes the sample, which absorbs light received from the light source

Prism(monochromator)= diffracts light into different wavelength

Slit= selects wavelength of the element

Detector/Recorder= detect the absorption of the light (energy in quanta) then records it in quantity.

assess the evidence which indicates increases in atmospheric concentration of oxides of sulfur and nitrogen

 

[Schoey93]

Fantastico! Chemica è molto difficile! Mamma mia!

I'm glad I didn't pick Chem, this marathon looks difficult and boring, and not worth it in the end! lol... please continue 'running'...