Answer:
Co (assuming there's a typo in not capitalizing the first letter)
Explanation:
The elements are depicted in the periodic table. Those are fundamental atoms that are not bonded to anything else but exist in their natural states without forming a bond with anything. That said, we're interested in a monoatomic species listed (the species which consist from only one single atom).
Out of all the choices, we have Co, cobalt, which is a single atom and can be found as an element with the atomic number 27.
Carbonic acid, 
, consists of 3 different elements: hydrogen (atomic number of 1), carbon (atomic number of 6) and oxygen (atomic number of 8). It's a compound rather than an element, as it consists of several atoms bonded together.
Oxygen, 
, is also a molecule. It consists of more than a single atom, even though the two atoms are identical. We have a compound, oxygen gas, which consists of two same oxygen (O) atoms (or elements).
Hydroxide anion, 
, also consists of two elements: oxygen and hydrogen. It also contains a charge on it, so rather than being a molecule, this is now an ion. Since it consists of more than a single atom, this is not an element as well.
Answer:
Empirical formula: CH
Molecular formula: C₆H₆
Explanation:
Based on the combustion of a hydrocarbon, the moles of CO₂ = Moles of Carbon in the hydrocarbon and the moles of H₂O = 1/2 moles of hydrogen in the hydrocarbon.
The empirical formula is the simplest whole number of atoms present in a molecule. With the moles of C and H we can find empirical formula:
<em>Moles C -Molar mass CO₂ = 44.01g/mol-:</em>
13.82g * (1mol / 44.01g) = 0.314 moles C
<em>Moles H -Molar mass H₂O = 18.01g/mol-:</em>
2.829g H₂O * (1mol / 18.01g) = 0.157 moles H₂O * (2mol H / 1mol H₂O) = 0.314 moles of H
The ratio of moles H: moles C:
0.314 moles / 0.314 moles = 1
That means empirical formula is:
<h3>CH</h3><h3 />
With the molecular weight and empirical formula we can find the molecular formula:
Molar mass CH = 12.01g/mol+1.01g/mol = 13.02g/mol
As the molecular weight of the molecule is 78.11amu = 78.11g/mol, there are:
78.11g/mol / 13.02g/mol = 6 times the empirical formula in the molecular formula
That means molecular formula is:
<h3>C₆H₆</h3>
Answer:
A. Precipitate reaction
Explanation:
The types of reactions are (1) combination or synthesis reactions. (2) decomposition reactions. (3) substitution or single replacement reactions. (4) metathesis or double displacement reactions
