Further Revsision

Question 1

How to calculate mass from yield

Answer 1

Find the mol of the molecule you know , then times this mol but the yeild as a percentage eg 0.76 then times mol by mr

Question 2

How to make a standard solution

Answer 2

Use information to find out moles then use moles to find out mass
Place weighting boat on digital balance and weight solid place the boat back on balance and subject values from each other
Add distilled water to dissolve solution
Tip into volumetric flask by using a funnel
Rinse the beaker string rod with distilled water to ensure no solute on the glass
Top the flask to the correct volume ,ensure meniscus reaches the line ,add the stopper and invert 10 times

Question 3

Indicator colour change

Answer 3

Methyl orange -red in acid and yellow in alkaline
Phenolphtalein -colourless in acid and pink in alkali

Question 4

Why put flask on white tile

Answer 4

Make it easier to see where the end point is

Question 5

Why are yields never 100 percent

Answer 5

unexpected reactions occur which don’t produce the desired product, not all of the reactants are used in the reaction, or perhaps when the product was removed from the reaction vessel it was not all collected.

Question 6

Titration concentration

Answer 6

If X reacts with Y at a certain concentration the mol of both solutions are the same