Answer:
See note in Explanation
Explanation:
The modern periodic table of the elements is arranged in order of increasing atomic numbers which is also in terms of the number of protons in the nucleus. That is, for any element listed on the periodic table its atomic number equals the number of protons in the nucleus. Thus, the element with 2 protons in its nucleus would be element #2 (Helium), element #3 (Lithium) has 3 protons in its nucleus and element #4 (Beryllium) has an atomic number 4 and contains 4 protons in its nucleus.
Also, this arrangement of elements finds that elements <u>below</u> elements 2, 3 & 4, Neon #10; sodium #11 & magnesium #12 have similar chemical and physical properties as does elements #2, #3 & #4. Such gives rise to the 'Periodic Law' => the chemical and physical properties of the elements is a periodic function of their atomic number (or, number of protons in the nucleus).
Answer:
0.43mol of Mg(OH)2
Explanation:
the molar mass of Mg(OH)2 is 58.319g/mol so you divide 25 by that and get the amount of moles.
Heat given out to the surroundings by the system = 225 J
Work done by the system on the surroundings = 645 J
According to the energy conservation, the energy can neither be created nor it can be destroyed, it can transform from one form to another. Hence, the energy which is lost to the surrounding as a work done and heat came from the internal energy of the system.
Hence, the change in the internal energy = - 225 - 645 = - 870 Joules
Negative sign means that the internal energy of the system is decreased by 870 Joules
Answer:
1) HCOOCH3
2) CH3CH2COOCH3
3) CH3CH2CH2CH(CH3)COOCH3
Explanation:
In the reaction between an alcohol and a carboxylic acid, an ester and water are formed. It is analogous to the inorganic neutralization reaction but this reaction is called esterification in organic chemistry. Esters contain the general formula RCOOR where the RCOO moiety was obtained from the acid and the other R moiety was obtained from the alcohol. The -COOR shows the ester linkage in the molecule. The condensed structural formulas shown in the answer reflects these facts.