Zinc Oxide 500g

While litmus paper may be used to determine whether an aqueous solution is an acid or a base, it not good for estimating the pH value of the liquid.

Aluminium Foil

Aluminum foil is suitable for many laboratory application, including sealing bottles, culture tubes,  , reducing evaporation or heat losses, covering corks, making weighing boats or dishes. May be used to cover vessels for autoclaving and incubating.