Goodbye privacy, hello 'Alexa': Amazon Echo, the home robot who hears it all. We had Rory Carroll invite âAlexaâ aka the Echo into his home. There was helpful cooking assistance, endless facts and figures, an amusing misunderstanding â and concerns over what exactly Amazon does with all that interaction data. Rory Carroll in Los Angeles.
Aqua regia or Royal water can dissolve metals. It is a mixture of conc.nitric acid and conc.hcl in the ratio of 1:3. Remember none of the above mentioned acids will dissolve the metals in the absence of other. adhi Â· 9 years ago.
If that doesn't dissolve all the tarnish, soak the pulls in ammonia for the same amount of time. Use ammonia only as a last resort; it's corrosive and may erase any light engraving on the metal. Jeanne Studio/Demand Media. Make a paste by dissolving a teaspoon of salt in 1/2 cup of vinegar and mixing in flour. Use the paste to rub dirt and discoloration from contours and corners and to polish the drawer pulls. Rub with a non-abrasive cloth to avoid scratching the metal. Clean the residue with another cloth.