Why is salt needed when using vinegar to clean pennies?
Apr 10, 2019 · Then you look at it 5 minutes later and the pennies are clean and looking like new again. I understand acid can etch the copper compound but why is the salt necessary for this …
By how much does borax reduce the melting temperature of gold?
Oct 25, 2021 · This you want to melt down into a single piece of gold. I have been told that the addition of borax powder reduces the melting temperature of gold, but I'm unsure of how much.
How does vinegar get rust off these coins - Chemistry Stack …
Feb 2, 2016 · The coins are most likely copper. The blueish-green rust is the patina of copper which is a mixture of various copper compounds like copper sulfate, copper carbonate, etc. …
Acetic (vinegar) and citric acid as the rust remover
Feb 21, 2017 · After 24 hours I have moderate results for acetic acid, and good results for citric acid. But in both cases, rust doesn't disappear fully. I have two question: If I mix two these …
home experiment - Different reactions of clean and rusty iron nails …
Jul 9, 2013 · When you dip a rusty iron nail in vinegar solution, the vinegar reacts with $\ce {Fe2O3.nH2O}$ (rusty iron or oxidized iron). Whereas in case of clean nail, it directly reacts …
Tape versus 1922 silver coin - Chemistry Stack Exchange
Apr 9, 2018 · This is more or less: estimates change and a coin is really only worth what you can actually sell it for, which is typically below the Red Book listing. As for cleaning, this is an …
inorganic chemistry - How pure gold is obtained back from …
Jul 1, 2019 · I know Aqua regia is used for purifying gold by dissolving gold in it, but how that dissolved gold is obtained back in the pure state? I searched everywhere, but I didn't get the …
everyday chemistry - Making sense of these recipes for removing ...
Aug 21, 2024 · Thanks! Plating with metal with a less tenacious oxide is a great idea - it also makes it much easier to ensure the parts are electrically grounded. These days electroless …
Why can we smell copper? - Chemistry Stack Exchange
Jan 20, 2014 · This is a nice question, as it confronts a very replicable and common experience with a well established yet seemingly contradictory fact. As you expected, the smell of metal …
Yellow stains after cleaning silver - Chemistry Stack Exchange
Aug 19, 2015 · I think that the silver piece was badly tarnished, you would need to reheat the baking soda and water mixture, and give the silver several treatments to remove all of the tarnish.