[tou]

Hi

There is an example in our book about heat energy (energetics).
I don't get this one bit, where they calculate the amount of NaOH. So, its not specifically about energetics but about the moles.
I will just outline it here:

20.0cm³ of exactly 2 mol dm^-3 aqueous sodium hydroxide is added to 30.0cm³ of hydrochloric acid of the same concentration, the temperature increases by 12.0°C. The total volume of aqueous solution is 50.0cm³ and the desnity of water is 1.00gcm^-3, hence the mass of the aqeueous solution is 50.0g.
(The amount of heat required to heat the water is calculated = 2.51kJ)

The hydroxide ion was the limiting reagent (amount of NaOH = c.V = 2 x 0.0200 = 0.0400 moles, amount of HCl = 2 x 0.0300 = 0.0600 moles), so 0.0400 moles evolved this amount of energy... etc...

The blue, bold part is what I don't get. Why did they divide 20cm³ by 1000?
Is it about converting to grams or something? If yes, does maybe someone know a good website about conversion?

Thanks!

[Borek]

mL -> liter, concentration is given as mol/L while volumes were given in mL.