Nitrogen vs Air in Car Tyres

The tread on my car tyres had worn down, so I popped into my local tyre retailer to buy 4 new tyres.

"We can inflate your new tyres with air, or, for an extra $5 per tyre we can fill them with nitrogen gas", the sales person told me, " Nitrogen gas doesn't react with tyre and rim material so your tyres will last longer, it will help maintain the pressure in your tyres so you won't need to check your tyre pressure as often, and it reduces the running temperature of the tyres so your tyres are less likely to explode."

Is this just marketing hype or are there good reasons for choosing to inflate your car tyres with nitrogen instead of air?

Read the March 2020 edition of AUS-e-NEWS to find out more.

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Chemistry Rockets to Mars

NASA is developing the most powerful rocket in history, the Space Launch System (abbreviated to SLS) to launch the spacecraft known as Orion. Orion is expected to carry humans beyond the Moon and on to Mars in the 2030s.
It is well known that engineers, physicists, mathematicians and computer programmers play a quintessential part in the design, development, launch, trajectory and landing of rockets and spacecraft, but what about chemists?
Chemistry also plays an important role in getting rockets off the ground.
Without an understanding of chemistry there would be no fuel, no thrust, no take-off!

Read more in the December 2017 issue of AUS-e-NEWS.

To subscribe to AUS-e-NEWS got to http://www.ausetute.com.au/ausenews.html

How many molecules are present?

Question: How many molecules are present in 4.21 mol of hydrogen gas?

Answer: 1 mole of anything contains 6.02 x 10²³ particles.
(Note that "mol" is the abbreviation for mole.)
So, 4.21 mol of hydrogen gas contains 4.21 x 6.02 x 10²³ = 2.53 x 10²⁴ molecules of hydrogen.

You can find a tutorial with worked examples at http://www.ausetute.com.au/namole.html