Calcium, Strontium, Barium

Sublimation. Perform the experiment in a fume cupboard ) Put the beryllium oxyacetate crystals into a test tube. Slightly tilt the tube with its mouth downward and carefully heat it in the flame of a burner. What happens What is the composition of the substance deposited on the tube walls Examine the crystals of the precipitated and sublimed beryllium oxyacetate under a microscope. What can this compound be used for in the technology of beryllium  

Pour 3-4 ml of a magnesium chloride solution into a test tube and add an ammonia solution. What happens Add a saturated ammonium chloride solution dropwise until the precipitate dissolves. How can the dissolution of the precipitate be explained Introduce into the test tube 1 ml of a sodium phosphate solution. What do you observe Examine the shape of the crystals under a microscope. What is the composition of the crystals Explain the processes that occur. Write the equations of the reactions. Pour hydrochloric acid into the test tube with the crystals. Explain the dissolving of the precipitate. 

How can the oxides, peroxides, and hydroxides of the alkaline-earth metals be prepared What are the commercial names of calcium and barium hydroxide solutions How do the solubility, basic properties, and thermal stability of the hydroxides change in the series calcium-strontium-barium  

Indicate the salts of calcium, strontium, and barium that are poorly soluble. How can you prove experimentally which of the calcium salts is the least soluble How does calcium oxalate react with acetic and hydrochloric acids How and why does the thermal 

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Lithium, sodium, potassium, rubidium, caesium beryllium, magnesium, calcium, strontium, barium)... 

Monofluorophosphates of ammonium, lithium, sodium, potassium, silver, calcium, strontium, barium, mercury, lead, and benzidine have been described (70) as have the nickel, cobalt, and ziac salts (71), and the cadmium, manganese, chromium, and iron monofluorophosphates (72). Many of the monofluorophosphates are similar to the corresponding sulfates (73). 

Beryllium, Magnesium, Calcium, Strontium, Barium and Radium... 

Monorubidium acetylide ignites in molten sulfur barium carbide ignites in sulfur vapour at 150°C and incandesces while calcium, strontium, barium and uranium carbides need a temperature around 500°C to ignite. 

Calcium, strontium, barium and radium, the alkaline earth metals proper, are the typical elements of the 2nd column (the 2nd group) of the Periodic Table. 

Beryllium and magnesium belong to the 2nd group of the Periodic Table together with calcium, strontium, barium and radium. Characteristic differences, however, may be noticed between the chemistry of Be and Mg and that of the alkaline earth s proper. Be has a unique chemical behaviour with a predominantly covalent character. The heavier elements (Ca, Sr, Ba, Ra) have a predominant ionic behaviour in their compounds. Mg has a chemistry in a way intermediate but closer to that of Be. Analogies between the Mg and Zn chemistries may also be underlined. 

As the number of elements increased, so did attempts to organize them into meaningful relationships. Johann Dobereiner (1780-1849) discovered in 1829 that certain elements had atomic masses and properties that fell approximately mid-way between the masses and properties of two other elements. Dobereiner termed a set of three elements a triad. Thus, chlorine, bromine, and iodine form a triad Dobereiner proposed several other triads (lithium-sodium-potassium, calcium-strontium-barium). Dobereiner recognized that there was some sort of relationship between elements, but many elements did not fit in any triad group, and even those triads proposed displayed numerous inconsistencies. 

Rosenberg [63] investigated the properties of sodium, potassium, calcium, strontium, barium, cadmium, cupric, copper, manganese, thallium and silver fulminates and compared them with mercury fulminate. Some of this results are shown in Table 24. 

With the exception of the calcium, strontium, barium and mercurous salts, the normal selenates are readily soluble in water. Barium chloride and mercurous nitrate are therefore convenient precipitation agents.6 Barium selenate is, however, more soluble than barium sulphate, and also differs from the latter salt in being slowly reduced to selenite by hydrochloric acid 7 for these reasons precipitation with barium chloride is not applicable to the quantitative determination of selenie acid. A concentrated solution of selenie acid which has been saturated with barium selenate deposits crystals of barium selenie acid, H2[Ba(Se04)2].8... 

If we examine the distances listed in Table 7.2 some interesting facts emerge. For a given metal A. the A—P distance is constant as we might expect for an ionic alkaline earth metal-phosphide bond. Furthermore, these distances increase calcium < strontium < barium in increments of about 15 pm os do the ionic radii of Ca2+. St7, and Ba- (Table 4.4). However, the B—P distances vary somewhat more with no periodic trends (Mn. Cu larger Ni, Fe, Co smaller). Most interesting, however, is the huger variability in the P—P distance from about 380 pm (Mn. Fe) to 225 pm (Cu). As it Luros Out, the lower limit of 225 pm (Cu) is a typical value for a P— P bond (Table E.l,... 

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