Calculate the number of moles of NaOH contained in 250. mL of a 0.05M solution.

0.0125mol

Explanation:

Molarity (M) = number of moles (n) ÷ volume (V)

n = Molarity × Volume

According to this question, a 0.05M solution contains 250 mL of NaOH. The volume in litres is as follows:

1000mL = 1L

250mL = 250/1000

= 0.250L

n = 0.05 × 0.250

n = 0.0125

The number of moles of NaOH is 0.0125mol.

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.