C5a-c

C5a-c

A mole of a substance has the same mass in grams as its relative formula mass (RFM)
The relative formula mass is the sum of the relative atomic masses
The relative atomic mass of an element is the average mass of an atom compared with 1/12th of an atom of carbon-12
The unit for relative formula mass (molar mass) is g/mol
Mass is conserved in a chemical reaction as no atoms are created or destroyed
the empirical formula gives the simplest whole number ratio of each type of atom in a compound
concentrations have units g/dm and mol/dm
volume is measured in cm or dm (1000cm = 1 dm )
Number of moles= concentration x volume (n=cv/1000)
the guideline daily amount lists on packaging may list the amount of sodium or the amount of salt
1. Salt is not the only source of sodium ions and so converting the amount of salt into sodium may not be accurate
The molecular formula of a substance is the actual number of each type of atom in one unit of the substance
This means that the GDA for sodium for a child is 39.3 ÷ 100 × 4 = 1.6 g. For an adult, it is 39.3 ÷ 100 × 6 = 2.4 g.

Resource summary

	Created by Rebekah Wills over 9 years ago