Acids and Bases
An acid is any substance whose aqueous solution is characterized by a sour taste, the ability to turn blue litmus red, and the ability to react with bases and certain metals to form salts. A Base is any substance whose aqueous solution is characterized by a bitter taste, a slippery feel, the ability to turn red litmus blue, and the ability to react with acids to form salts. Questions about the acidity and alkalinity of solutions and different types of acids and bases are found n our Acids and Bases category.
Asked in Science, Chemistry, Acids and Bases
What are some examples of chemical and physical changes?
Physical Changes Change of state (such as from solid to liquid or from gas to liquid) Specific examples of state change include water freezing, alcohol evaporating and dry ice (solid carbon dioxide) subliming Absorption of water into a towel Crumpling a piece of paper Pulling copper into a thin wire - a change of shape, but not a change of composition Cutting a material such as wood Tearing a piece of tin foil Breaking glass Deflating a basketball Mixing different solids (such as solid sulfur and iron filings) Inflating a volleyball Cloud forming in the sky Chemical changes Burning a log of wood Mixing an acid with a base, producing water and a salt. Photosynthesis - a process in which carbon dioxide and water are changed into sugars by plants. Cracking heavy hydrocarbons to create lighter hydrocarbons (part of the process of refining oil). Cooking examples: popcorn, cake, pancakes, and eggs Oxidation examples: rust or tarnishing Combustion Mixing chemicals Rotting of fruit Cooking rice Explosion of fireworks Tarnishing silver Lighting a match Chewing/digesting food Rusting nail Burning gas in a stove Oxidizing food for energy Roasting a marshmallow Adding food coloring to icing Frying an egg Burning a magnesium strip The following can indicate that a chemical change took place, although this evidence is not conclusive: Change of color (for example, silver to reddish-brown when iron rusts) Change in temperature or energy, such as the production (exothermic) or loss (endothermic) of heat Change of form (for example, burning paper) Light, heat, or sound is given off Formation of gases, often appearing as bubbles Formation of precipitate (insoluble particles) The decomposition of organic matter (for example, rotting food)
How do you use muriatic acid to etch concrete?
For anyone interested in the TRUE HCl concentration of muriatic acid (sans WIKIfication) simply google "muriatic acid msds" and you will see that, while the concentration varies by manufacturer, it generally ranges from 33-40%. Furthermore, even if you order HCl by name from a chemical supply house, you order by concentration, usually some reagent grade, with fuming HCl starting at ~40%. No hardware store in the world sells 100% HCl for etching concrete. DANGER / SEVERE HAZARD -- Muriatic Acid IS UNDILUTED (100% concentration) Hydrochloric acid. Wear Eye and face protection, acid resistant gloves, rubber slicker suit, or be VERY careful as Hydrochloric acid is highly corrosive and can instantly burn holes in your skin and tissues, and right through all woven clothing. When diluting ANY acids, it extremely important that you NEVER ADD WATER TO ACID, as the reaction between the two will result in an "explosion" throwing acid instantly in all directions. The PROPER method of diluting acids is to very SLOWLY pour the concentrated acid into a larger volume of water. For an additonal "layer" of safety, do not pour the acid from a large and heavy container, as it is more difficult to handle and control. Pour the needed amount of concentrated acid into a smaller, acid resistant, container which will be easier to handle and therefore control the pour rate. When using baking soda for neutralizing acid residues, be VERY CAREFUL to NOT ALLOW the baking soda to contact the UNDILUTED ACID as the resulting reaction can be explosive! 1 Bust out some protective clothing and a gas mask. Have a good supply of fresh water on hand in case you need to rinse any body parts. Be very careful with muriatic acid; it's 30% hydrochloric acid, and is fairly hazardous. If you only want to barely 'etch' a slippery concrete surface, it is best to dilute the acid with water, as acid straight from the bottle tends to be very aggressive with any concrete surface, and can badly damage the surface very quickly. For a deeper etch Pour the substance where you want to etch the concrete and spread it out with a nylon broom. let it sit for a half-hour. Wash it thoroughly with the hose after. I have used a small hand held spray bottle set to a fine misty spray, and skipped the 'rinse' step altogether with very good results. 'Baking Soda / water solution' is an acid neutralizer, and can be used around most landscape with safe results. >>> Get used to the process FIRST. Buy a few cement blocks, bricks, or slabs that you can throw away. Different concrete blends, strengths,... react differently. New and old concrete of the same formula will also react differently. An new slab poured next to the exact same mix from the same company in an old slab will be different due to moisture content and curing time). Good luck. - email@example.com #3, You follow the MFG directions on the product as with anything. You use Ammonia to neutralize.
Asked in Chemistry, Acids and Bases, Metal and Alloys
What happens when dilute acids react with chemically active metals?
Asked in Chemistry, Organic Chemistry, Acids and Bases
Why para nitro phenol is more acidic than meta nitro phenol?
Para nitrophenol is more acidic than meta nitrophenol because the deprotonated cation for the para form is able to delocalize the positive charge over the ring AND the nitro group, whereas the meta form is only able to delocalize over the ring. Thus the para ion is more stable, so the products for an acid-base reaction are more favoured for the para than for the meta.
Asked in Acids and Bases
Is LDA a base?
LDA is a base, and a strong one at that with a pKa of approximately 25 It is typically used for removing hydrogen atoms for aldol reactions since this makes the reaction irreversible and prevents various side reactions occuring. LDA has 2 isopropyl groups attached to a central nitrogen atom which yields a negative charge making the compound basic.
Asked in Plumbing, Waste and Recycling, Acids and Bases
How do you dispose of Liquid Fire Drain Opener?
How to rid yourself of Liquid Fire The best way to dispose of it would be to pour small amounts down the drain, wait awhile, and then flush it out with some water. Repeat this while waiting in between sessions because the water will cause the drain opener to heat up quite a bit. If you want to keep the flora in your septic tank alive it would be best to neutralize it. Liquid fire is sulfuric acid. You can first carefully mix it with a base thus creating a salt and water and then flushing down the drain. Common bases you could find around your house are baking soda (sodium bicarbonate) and ammonia water (ammonium hydroxide). The latter will actually flush fertilizer (ammonium sulfate) down your drain :) Answer Your local town or county should have a place where you can dispose of chemicals that you no longer want to use, such as paint, paint thinner, fertilizer and so on. This is much better than tossing it into the regular garbage or into the sewage system.
What's the reaction between coke and salt?
I am not too sure about what you are asking. In chemistry, coke is simply carbon. Salt is any ionic compound formed by a neutralization reaction between an acid an a base. Generally, all salts do not react with carbon, no matter what form the salt is in (i.e. solid or aqueous). * Added by Zaminlove: I think that coke stands here for Coca Cola! It frothes up. * Another note: Yes, in US slang coke is Coca-Cola. And sodium chloride (and other substances) can catalyze the violent releasing of carbon dioxide from this coke, forming a column as a little geyser. For a detailed discussion see the link below.
Asked in Acids and Bases
What happens when a metal reacts with acid?
A chemical reaction; the resulting substance is a salt. I would need to know what type of metal you are talking about. All metals react different to acid, the key is to use the correct acid chemistry to achieve what you are trying to do. Mix Nitric Acid and 400 series SS, a little more than salt with happen lol
Asked in Acids and Bases, Yogurt
Is yogurt a base or acid?
PLAIN yogurt with no fruit, sugar, or sweetener added has a pH of around 4. So it is a little acidic BUT the way it processes in your body, because of the live cultures, it changes pH during digestion (ONLY PLAIN YOGURT) - kind of like lemon or RAW apple cider vinegar. I always add fresh lemon juice to anything questionable - water, white/green tea, yogurt. Lemon is a fruit you can combine with all other foods. Don't forget you should eat alkaline fruit by itself, with nothing else (other than other fruits) b/c acidity increases if you mix fruit w/ carbs, fats, and even alkaline vegetables during digestion.