The pH of vinegar (acetic acid) is 2.5, it is a weak acid. Vinegar is produced by a fermentation process from alcohol. Vinegar sold in supermarkets it not pure acetic acid, it has been diluted.
Does it actually work as a fabric softener?
People love using vinegar in their laundry. There is an urban myth that it acts as a fabric softener, unfortunately the chemistry of how fabric softeners work does not to support this. Choice.com found vinegar to be no more effective than washing in water alone.
What happens when you add baking soda to vinegar?
People also love using vinegar and baking soda (sodium bicarbonate) for cleaning. When baking soda and vinegar are combined, an acid base reaction occurs immediately, this reaction is exothermic ie. energy releasing, followed by a rapid decomposition reaction, which creates water and carbon dioxide. Because of the rapid decomposition, this method is not actually very useful for cleaning.
Does it sanitise? Is it antibacterial?
4.2% acetic acid has been found to be effective against one type of fungus, Penicillium chrysogenum .
Unfortunately there is no other evidence to support the use of vinegar as a broad spectrum antibacterial product, at least not yet.
When vinegar is added to a large quantity of water, there is very little change to the pH of the water, and the functional acetic acid component is diluted to a point that whatever anti fungal properties it has, become ineffective, it will not sanitise.
What is vinegar useful for?
What vinegar is useful for is dissolving concrete dust, it can be used to clean filters and the inside of washing machines, although neat vinegar is required which is corrosive and will eventually damage seals and other parts. It not recommended to clean washing machines with vinegar unless absolutely necessary, like in this unique situation, for this reason. Other options such as a drum clean cycle or dilute bleach wash are effective and won’t damage the machine. The acidity of the vinegar dissolves the concrete dust, which is very basic.