a solution A is HCl and a solution B is 2g of water in 500cm³ solution. indicator: methyl orange. Procedure:pipette volume=25cm³end point after titration 24.5cm³.(1)calculate mass concentration of the base in g/dm³ (2) calculate molar concentration of the base in mol/dm³(3)calculate mass concentration of the acid in mol/dm³(4)calculate mass concentration of the acid in g/dm³(5) masses of acid and base neutralize to each other(6) is the reaction a neutralization reaction. Why?

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.