Quiz - chemical attractions
Do you know the slowest converting natural radioisotope? View Solutions
So far the most stable bismuth 209 is subject to radioactive decay with a half-life of alpha over 20 billion billion years.
Did you know that there is a reversible inorganic acid-base indicator with the transition in the visible spectrum?
Know how to dissolve the potassium permanganate in benzene (normally insoluble in benzene)? View Solutions
Potassium can shake out of the aqueous phase into benzene after addition crownetheru which vykomplexuje potassium jonty. Created the so-called naked (naked) jont permanganate, which creates the benzene sandwich structure.
Why are ponds do not freeze from the bottom as the "decent" liquids habit? Note that it is perfectly lovoli fish. He would only have to wait until winter is just a ezbírat. View Solutions
This is because the so-called anomalies of water. At approximately 4.4 ° C, the maximum density. In the range of 4.4 to 0 ° C, the density decreases and therefore colder water flows to the surface where freezing and conversely hotter water flows down to the bottom.
It is more correct notation P 2 O 5 and P 4 O 10? Netipujte and try to justify it. View Solutions
The oxidation of phosphorus initially created tetrahedron P 4 (white phosphorus), which is then gradually oxidized and form the oxides of phosphorus.
There may be two different modifications of hydrogen (H isotope one molecule of H 2 in the liquid state)? If yes, how they differ. View Solutions
This is the para and ortho-hydrogen. Ortho hydrogen is consistent rotation of hydrogen atoms, hydrogen para opposite. This is also due to the different boiling points.
There is an insoluble (in water) nitrate pominelemi nitrates organic substances (substance is soluble if it dissolves more than 1 g per 100 g water). View Solutions
It is an alkaline bismuth nitrate 4BiNO 3 · Bi (OH) second
Bromistan potassium was first prepared rather curious way, do you know how?View Solutions
Prior to its preparation, a scientist quantum chemical calculations proved impossible to prepare bromistanů (mistake Creeps).
Bromistan was first prepared nuclear reaction, followed by oxidation of fluoride xenoničitým who managed to overcome the high activation energy of reaction (first held Appelmann). 83 SeO 4 ---> 83 BrO 4 -
It is a wonder, but under certain conditions it is possible ordinary scissors cut glass windowing. Your task is to identify these conditions. Small clarification. Temperature and pressure are measured under standard conditions, the thickness of the glass does not exceed 2 mm. View Solutions
Sheet glass to a thickness of 2 mm can be cut under water, which compensates the tension of glass and prevents cracking (this can be cut as wheel, etc..).
The glass is generally known that the sudden change in temperature bursts. However, there is glass which can be heated in the flame of a gas burner to red heat and immediately immersed in a stream of cold water and the material can withstand. You can tell from the description of that glass is, or why it has such properties. View Solutions
One such example is quartz. This thermal resistance is the result of nearly zero thermal expansion.
Maybe you've ever encountered during disassembly and cleaning of the boiler with a metal rod placed inside, which is bonded to the metal shell boiler. I'm sure you can identify what it is for, but the principle of how it works will be worse. View Solutions
She rod is magnesium alloy. The less noble metal together with a metal sheath heater consists of an electrochemical cell. Oxidation, which would normally carried on an iron boiler shell is due to the lower reduction potential of the magnesium rod.
Conductivity is primarily the domain of metal or some plastic or ceramic materials doped with halogens. However, there is a plastic containing only hydrogen and hlík which also conducts electricity. Do you know him? View Solutions
This is a polyacetylene.
Most liquids or suspensions which are commonly encountered are referred to as Newtonian fluids ie their viscosity ("how well fluid flow") is a function of temperature only. However, there are non-Newtonian fluid, where viscosity is a function of temperature and "stirring speed" (exactly dv x / y). View Solutions
Newtonian fluid: µ = µ (T) is the viscosity of water as a function of temperature, molten glass, etc..
Non-Newtonian fluid: µ = µ (T, v) the viscosity is a function of temperature and stirring speed for example??? ie, the longer the liquid or slurry mix that the viscosity decreases or increases one second This process is reversible (stop when mixed liquid obtained initial viscosity)
Your task is to find two nenewtonowské liquid (suspension) tip 1 and 2, which are commonly encountered.
The liquid first type: for example ketchup, just shake and flows much better
Fluid second type: for example, wet sand, the stirring impeller forms a crust around the sand and water left sides
Do you know what are the differences in the mathematical apparatus (necessary equations and constants) for the design of production (rounding cones - salami and blocks - bricks) sausage and bricks? Bricks and salami extrude a suitable hole and Reza to the required length. View Solutions
No, calculation using the same mathematical vstahy: continuity equation (balance equation), Cauchy equations and constitutive equations.
Vanadium has its compounds as 5 different colors. Can you assign colors to each of the compound? View Solutions
purple - VSO 4
Yellow - Navoi 3
red - polyvanadíčnany stable at pH = 0-1
green - V 2 (SO 4) 3
blue - wasp 4