Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol.
Answer:
here are some examples of physical change!!!
Explanation:
-An ice cube melting into water in your drink.
-Freezing water to make ice cubes.
-Boiling water evaporating.
-Hot shower water turning to steam.
-Steam from the shower condensing on a mirror.
A volumetric flask is used to contain a predetermined volume of substance and only measures that volume, for example 250 ml.
Conical flasks can be used to measure the volume of substances but the accuracy they provide is usually up to 10ml. Conical flasks are used in titrations, reactions where the liquid may boil, and reactions which involve stirring.
Pippettes are of two types, volumetric and graduated. Pippettes are used where high accuracy is required and volumetric pippettes come in as little as 1 ml. Pippettes are usually used in titrations.
Graduated cylinders come in a wide variety of sizes and their accuracy can be down to as much as 1 ml. They are used to contain liquids.
Because <span>Gold is a very inert metal, and won't really react with oxygen in the air.
The only reason other metals tarnish, such as copper, silver, steel/iron, is
because they're freely reacting with air, to produce a metal oxide surface layer. </span>
