100ml bottle of 0.5% phenolphthalein solution. This is used to show the end-point during titrations and is a part of the Acidity meter (acidometer kit available elsewhere in our eBay shop). This solution is known as the indicator and during the addition of N/9 sodium hydroxide, changes from colurless to purple-red at the neutralisation point. Also sold in 25ml, 50ml and 500ml sizes.

Both items are required when determining the acidity of milk or whey during the cheesemaking process and spare 500ml, 1litre and 5litre bottles of N/9 sodium hydroxide (titrant) are also available elsewhere in our Ebay shop. 

We sell over 100 items in our eBay shop, that vary in weight from 3g to 50kg, so I'm sure you can appreciate that it is impossible to devise a postage system that covers every possible purchase combination! That is why we stress that if customers are buying multiple items, then please ask for an invoice first; that way it gives us a chance to correct the postage part accordingly.