Answer:
SO42 - Trigonal planar ion
Explanation:
The SO4^2- ion is tetrahedral and not trigonal planar because the sulphur atom has four regions of electron density which includes the lone pair of electrons on sulphur atom.
This accounts for the observed tetrahedral arrangement of electron pairs around the central sulphur atom in SO4^2- ion, hence the answer.
The molecular formula for the compound is 
<u>Explanation</u>:
As with all of these problems, we assume 100 g of an unknown compound.
And thus, we determine the elemental composition by the given percentages.
Moles of carbon = 85.64 / 12.011
= 7.13 mol.
Moles of hydrogen = 14.36 / 1.00794
= 14.25 mol.
There are 2 moles of hydrogen per mole of carbon. And thus the empirical formula is CH
.
And molecular formula = n × (empirical formula)
Thus, 42.08 = n × (12.011 + 2 × 1.00794)
And thus n = 3, and molecular formula =
<span>Molality(m) or molal concentration is a measure
of concentration and it refers to amount of substance in a specified amount of
mass of the solvent. Used unit for molality is mol/kg which is also
sometimes denoted as 1 molal. It is equal to the moles of solute (the substance
being dissolved) divided by the kilograms of solvent (the substance used to
dissolve).</span>
Molarity(M) or molar concentration is also a
measure of concentration and represents the amount of substance per unit volume
of solution(number of moles per litre of solution. Used unit for molarity is
mol/L or M. A solution with a concentration of 1 mol/L is equivalent to 1 molar
(1 M).
Molality is preferred when
the temperature of the solution varies, because it does not depend on
temperature, (neither number of moles of solute nor mass of solvent will be affected
by changes of temperature), while molarity changes as temperature changes(volume
of solution changes as temperature changes).
When to positive atoms connect
Electrons because electrons are found in the electron cloud outside the nucleus.
