All Solutions
Section 5-6: Ionic Compounds
Magnesium Mg is a metal while oxygen O is a non-metal, therefore the bond formed between them will be an ionic bond. Here magnesium metal will lose 2 of its valence electrons while oxygen will gain these 2 electrons to form MgO.
Zinc Zn is a metal while chlorine Cl is a non-metal, therefore the bond formed between them will be an ionic bond. Here Zinc will lose 2 of its valence electrons while will be gained by 2 atoms of chlorine to form ZnCl$_2$.
Carbon C and fluorine F are both non-metals therefore the bond formed between them will be covalent in nature and formed by sharing of electrons instead of transfer.
Hydrogen H and fluorine F are both non-metals therefore the bond formed between them will be covalent in nature and formed by sharing of electrons instead of transfer.
Magnesium is a metal while chlorine is a non-metal.
Atomic structure of magnesium atom:
Atomic structure of chlorine atom:
It can be seen that magnesium has 2 valence electrons which it will need to lose to obtain the stable noble gas configuration and form an ion with a positive 2 charge.
It can also be seen that chlorine has 7 valence electrons and it requires 1 electron to obtain the stable noble gas configuration and form an ion with a negative 1 charge.
One magnesium atom will lose both of its valence electrons and form Mg$^{+2}$. These electrons will be gained by 2 atoms of chlorine to form 2 chloride ions, 2Cl$^{-1}$. The equation becomes:
$$
mathrm{Mg{(s)} + Cl_{2(g)} longrightarrow MgCl_{2(s)}}
$$
Lithium is a metal while oxygen is a non-metal.
Atomic structure of lithium atom:
Atomic structure of oxygen atom:
It can be seen that lithium has 1 valence electron which it will need to lose to obtain the stable noble gas configuration and form an ion with a positive 1 charge.
It can also be seen that oxygen has 6 valence electrons and it requires 2 electrons to obtain the stable noble gas configuration and form an ion with a negative 2 charge.
Two lithium atoms will lose one electron each and form 2Li$^{+}$. These electrons will be gained by 1 atom of oxygen to form oxide ion, O$^{-2}$. The equation becomes:
$$
mathrm{4Li_{(s)} + O_{2(g)} longrightarrow 2Li_2O_{(s)}}
$$
NaF dissolves in water to release Na$^{+}$ and F$^{-}$ ions. It can be seen that 1 Na and 1 F join together to form 1 molecule of NaF therefore they break to form ions in equal or $1:1$ ratio, when dissolved in water.
Li$_3$N dissolves in water to release Li$^{+}$ and N$^{-3}$ ions. It can be seen that 3 Li and 1 N join together to form 1 molecule of Li$_3$N therefore they break to form ions in $3:1$ ratio, when dissolved in water. This implies that for every 1 nitride ion, there are 3 lithium ions.
FeCl$_3$ dissolves in water to release Fe$^{+3}$ and Cl$^{-}$ ions. It can be seen that 1 Fe and 3 Cl join together to form 1 molecule of FeCl$_3$ therefore they break to form ions in $1:3$ ratio, when dissolved in water. This implies that for every iron ion, there are 3 chloride ions.
K$_2$O dissolves in water to release K$^{+}$ and O$^{-2}$ ions. It can be seen that 2K and 1 O join together to form 1 molecule of K$_2$O therefore they break to form ions in $2:1$ ratio, when dissolved in water. This implies that for every 1 oxide ion, there are 2 potassium ions.
Element X with 3 electrons in its outermost orbit. This implies that it is a metal and will lose these 3 electrons to form X$^{+3}$ ion.
Element Y with 7 electrons in its outermost orbit. This implies that it is a non-metal and it needs to gain 1 electron to form Y$^{-}$ ion.
One atom of Element X will lose 3 electrons to form X$^{+3}$ ion. One atom of Element Y can gain only one of these 3 electrons to form the ion Y$^{-}$. Therefore, 3 atoms of Y will be needed to form the compound here, and so the chemical formula of this compound will be XY$_3$.
Pure water is a non-conductor of electricity. This is because it is a covalent compound and molecules of H$_2$O are not ionized in it to participate in electrical conduction.
Tap water and seawater are good conductors of electricity as both of them have salts (and minerals) dissolved in them. These ionic compounds dissolved in water also ionizes H$_2$O molecules to H$^{+}$ and OH$^{-}$ which also participate in electrical conduction. Seawater is a better conductor of electricity than tap water as the concentration of ions in seawater is greater than that of tap water. This means that more ions are available for electricity conduction making it a better conductor of electricity.
Table:
A scatter plot of the data is plotted (green) and a best fitting line is drawn (red):
Francium lies in the 7th period. It can be seen that the red best fitting line intersects the line $x=7$ at $y=580$, therefore it can be concluded that the melting point of francium chloride is approximately $580text{textdegree}$C.
