Titration and Mole Calculations

Question 1

One mole of atoms

Answer 1

6 x 10^23 atoms

Question 2

Number of moles equation

Answer 2

N = mass divided by molar mass

Question 3

Mass equation

Answer 3

Mass (g) = number of moles x molar mass

Question 4

How many moles of solute in solution equation

Answer 4

Number of moles dissolved = concentration (moldm^-3) x volume (dm^3)

Or if volume in 1000cm^3
N = c x v divide by 1000
So c = n x 1000 divide by v

Question 5

Titration procedure

Answer 5

• Set up clamp stand to hold burette
• Use a funnel to fill burette with 0.1moldm^3 of hydrochloric acid
• Record initial volume
• Use pipette to add 25.0cm^3 of sodium hydroxide solution to conical flask and add a few drops of phenolphthalin indicator to make alkaline solution turn pink
• Open burette tap to add acid to flask and shake gently
• When solution turns colourless it has reached end point
• Record burette volume for rough result
• Repeat until you have 3 titres

Question 6

Why is it important to remove funnel once you’ve filled burette with acid?

Answer 6

Drops of acid remaining in funnel could fall into burette after initial volume has been recorded