<span>Chemically speaking, rust is a base and any acid will remove it. The choice of acid is going to be the thing to consider, since acid + base = salt and water. Phosphoric acid left a residue because the salt Iron phosphate is insoluble in water. Iron's soluble salts include the chloride, the sulfate and the nitrate. Industrially speaking, you need to "pickle" your iron. Pickling is a process in which dilute sulfuric acid is used to remove any surface corrosion prior to either painting or plating an iron surface. Sulfuric acid is ordinary battery acid and the salt Iron sulfate is not toxic. Sulfuric acid is one of the most common acids used (besides hydrochloric acid). The dilute kind is not terribly corrosive but concentrated sulfuric acid is a thick, syrupy liquid which can cause some nasty chemical burns if allowed to remain on the skin. It also heats up quite a lot when water is added, so this is an "Acid to water not water to acid" situation. The other choice is Hydrochloric acid, known as muriatic acid. The 20% concentrate is available in nearly any hardware store. It isn't as corrosive as concentrated sulfuric acid, but it has a burning, acrid stench, so never use the concentrate without adequate ventilation. It is ordinarily used to remove hard water deposits (boiler scale) but does a good on on rust as well. Concentrated Iron chloride isn't entirely inert but lots of rinsing will turn it back into harmless rust/sludge, especially if the rince water is naturally hard. Nitric acid will remove corrosion from anything, but it is extremely corrosive, smells worse then Hydrochloric acid and isn't easy to get, since it can be used to create some powerful explosives</span>
Answer:
13.20 cm/s is the rate at which the water level is rising when the water level is 4 cm.
Explanation:
Length of the base = l
Width of the base = w
Height of the pyramid = h
Volume of the pyramid = 
We have:
Rate at which water is filled in cube = 
Square based pyramid:
l = 6 cm, w = 6 cm, h = 13 cm
Volume of the square based pyramid = V
Differentiating V with respect to dt:
Putting, h = 4 cm
13.20 cm/s is the rate at which the water level is rising when the water level is 4 cm.
The formula of butane is C4H10 but I don't how many atoms it contains though
Solid-When a solid is heated the particles gain energy and start to vibrate faster and faster. Initially the structure is gradually weakened which has the effect of expanding the solid. Further heating provides more energy until the particles start to break free of the structure. Although the particles are still loosely connected they are able to move around. At this point the solid is melting to form a liquid.
Liquid-As the liquid gets warmer more particles have sufficient energy to escape from the liquid. Eventually even particles in the middle of the liquid form bubbles of gas in the liquid. At this point the liquid is boiling and turning to gas. The particles in the gas are the same as they were in the liquid they just have more energy. At normal atmospheric pressure all materials have a specific temperature at which boiling occurs. This is called the "boiling point" or boiling temperature.
Description of Phase Change Term for Phase Change Heat Movement During Phase Change
Solid to liquid Melting Heat goes into the solid as it melts.
Liquid to solid Freezing Heat leaves the liquid as it freezes.
Liquid to gas Vaporization, which includes boiling and evaporation. Heat goes into the liquid as it vaporizes.
Gas to liquid Condensation Heat leaves the gas as it condenses.
Solid to gas Sublimation Heat goes into the solid as it sublimates.
Answer:
b. E = 2,28V
Explanation:
The maximum work is the same than ΔG. As ΔG could be written as:
ΔG = nFE <em>(1)</em>
Where n is moles of electrons transferred, F is faraday constant (96485 J/Vmol) and E is the voltage of the cell.
For the reaction:
CH₃OH(l) + ³/₂O₂(g) → CO₂(g) + 2H₂O(l)
The oxidation state of C in CH₃OH is -2 but in CO₂ is +4, that means transferred electrons are +4 - -2 = <em>6e⁻</em>
Replacing in (1):
1320x10³ J = 6mol e⁻×96485J/Vmol×E
<em>E = 2,28V</em>
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I hope it helps!
