This quick post will be a little different, I will be comparing the use of household materials in the form of glass and plastic containers with the use of laboratory glassware. The latter is obviously better for many reasons but once money is considered how do they fare? (also I got new glassware!!)
Proper equipment can be expensive. I often reuse various glass and plastic containers that can safely store chemicals, or can withstand the conditions of a reaction to act as a reaction vessel. I feel like a beggar in my household as I am asked the routine question “Can I throw this jam jar away or would you like to keep it”. If anything I aid in the reuse of products before they are thrown away, although this can sometimes quite quickly end in the death of the poor container.
For example, as useful as PET (polyethylene terephthalate) plastic is in the form of extremely common plastic drinks bottles, it is easily hydrolysed by sodium hydroxide, limiting its use as a reaction vessel. Knowing my boundaries, I have produced hydrogen by reacting aluminium with fairly dilute sodium hydroxide in a PET container. The reaction went safely and expectedly without the requirement of the safety precautions put in place so it is usable. But now I was curious; what did it take to destroy the plastic? I ended up leaving the bottles in an arbitrary concentration of sodium hydroxide just to witness the damage to the bottle it could cause so I would know what to look for in the future. The damage consists of a build up of a white solid – the hydrolysis product, the monomer terephthalic acid – followed by a hole that develops in the wall of the bottle, eventually consuming the bottle.
Sometimes you have to get creative and make your own equipment from various objects. I plan to write a post soon (EDIT: it has been released!) on the synthesis of alkali metal hydroxides by membrane electrolysis which required me to experiment with building an electrolysis cell. Most of the prototypes consisted of two plastic containers connected by a small plastic tube, secured together with hot glue. I know, very scientific, but it works enough to be viable for the crude small-scale synthesis.
Although plastic containers are often cheaper and larger, glass is more inert and can withstand higher temperatures than plastic giving it the edge in versatility, proved by my jam jar collection of varying sizes. My red phosphorus enjoys the humble abode of a tiny jam jar. It is also easier to find glass storage containers of many sizes to buy at various stores.
This is all fine and dandy – it is fun to repurpose household containers – but sometimes you just want a good old specialised borosilicate beaker as a reaction vessel. Scientific glassware breaks just as easily as I found out the hard way but there are reasons for their relatively expensive prices! With a lower thermal expansion, borosilicate glass can withstand higher temperatures and uneven heating before cracking than its common soda-lime glass counterpart, allowing for more direct heating. If you pay for the higher quality brands, such as Pyrex or Quickfit, it is unlikely you will have to deal with bubbles in your glass that can make glass more sensitive to cracking due to uneven heating. Also the approximate graduations and the easy-pour tip are easily overlooked yet very useful features.
To a certain point household containers coupled with a few inconveniences can deal with most jobs of a beaker or a reagents bottle, but there are some things they simply cannot do. Starting off very simple is the conical flask. The tall conical shape, hence its name, is great for preventing bumping or spitting mixtures from leaving the flask as well as conveniently making for a great vessel for the Elephant’s Toothpaste experiment due to the building up of pressure from the narrow neck. The shape also makes it less prone to being knocked over; saying that I think I know a friend who could benefit from a conical flask as a drinking vessel…
The measuring cylinder on the other hand is very easy to knock over due to its long and thin shape. This shape though enables very accurate measuring where a single drop of a liquid noticeably moves the meniscus upwards compared to the wide beaker where almost no difference to the position of the meniscus is made. Chemistry is all about being accurate so the measuring cylinder is a must-have for any serious amateur and above.
A few bits of equipment, such as glass stirring rods, you only realise are so useful once you get them. The equivalent in poor terms may be a stainless steel spoon but this can interfere with some reactions. My sister who deals with dyes has mentioned how a few times she has managed to make stainless steel spoons go green when stirring dye mixtures, probably from an oxidation state of chromium. Glass pipettes and Pasteur pipettes are great for transferring small volumes of liquid but do not really have an equivalent apart from glass droppers or plastic syringes from some medically related products.
When it comes to performing a distillation or heating under reflux, you would have to be crazy to design your own equipment. The perfect fit of all the joints of the bought glassware is very difficult to achieve at home for a start. Imperfect fits can cause dangerous leaks that can threaten your safety so I highly recommended to just find the money for the proper safe equipment. I plan to invest soon in a decent quality hot plate magnetic-stirrer as I feel uncomfortable heating my equipment with my spirit burner and the lack of controlling the temperature is limiting what I can do.
In conclusion, glass and plastic containers around the house can be great for storing chemicals but when it comes to acting as a reaction vessel, it’s worth the money to ensure proper and safe equipment, especially once it gets to complicated equipment.