# 5 - Formulae, Amounts Of Substance Flashcards

What’s avogadros constant?

6.02 x 10^23

What is the R constant

8.314

What is the ideal gas equation?

PV = nRT

Calculating moles?

mass / rfm (molar mass)

Moles/ rfm/ mass triangle?

mass on top! moles and rfm on bottom

Unit for pressure?

Pascals (pa) 1kpa = 1000pa

Unit for volume?

m^3

Converting from degrees centigrade to Kelvin?

+ 273

Using empirical formula?

divide the mass by the rfm for all given elements

if the ratio is clear then leave it

if not divide by the smallest

work out the ratio

Ionic equations?

break down all elements into their ions

cancel out ions either side of the equation

rewrite with what’s left

Gas triangle?

volume on top, moles and 24 on bottom

Volume of most gases at r.t.p

24