Answer:heat of vaporization of water = 2257 J/g
Explanation:
Answer:
a. The formula for tritoborate ion is B₃O₈²⁻
b. The formula of the compound formed will be Fe₂(B₃O₈)₃ and the name will be Iron (iii) tritoborate
Explanation:
The formation of compounds by atoms of elements occurs in accordance with the valencies of the elements. Valency refers to the combining power of an element. For metallic elements, it is usually the number of electrons they can give up or lose while for non-metallic elements, it is the number of electrons they can accept. The valency of an atom of an element is related to its oxidation number. Metals have positive oxidation numbers while non-metals have negative oxidation numbers. Sometimes, two or more atoms combine together and react as a single unit and may carry a positive or negative charge. These are known as a radicals. For example, ammonium ion, NH₄⁺.
In the given question, calcium tritoborate, CaB₃O₈ is formed from the combination of calcium ion and tritoborate ion. Calcium ion carries the charge of +2, therefore, the tritoborate ion must have a charge of -2 in order to form a compound since the overal charge on a compound is zero.
a. let the tritoborate ion be represented by X
Ca = +2, X = ?
+2 + X = 0
X = -2
Thus, the formula for tritoborate ion is B₃O₈²⁻
b. When tritoborate ion combines with iron (iii) ion, Fe³⁺, two moles of Fe³⁺ will be required to react with three moles of B₃O₈²⁻ in order to have a neutral compound. The formula of the compound formed will be: Fe₂(B₃O₈)₃ and the name will be Iron (iii) tritoborate
Answer:
Answer in explanation
Explanation:
a. Boron , element 5
Helium has 2 electrons, add to the other 3 to give 5.
Other group members are : Aluminum Al, Gallium Ga, Indium In , Thallium Tl and Nihonium Nh
b. Sulphur, element 16
Neon is 10 , add other 6 electrons to make 16
Other group members are: Oxygen O, selenium Se , Tellurium Te and Polonium Po
c. Lanthanum, element 57
Xenon is 54, add the other 3 electrons to give 57.
Other elements in group : Scandium Sc , Yttrium Y , Actinium Ac, Lutetium Lu and/or Lawrencium Lr
