Answer:
Where SiO2 has strong covalent bonds between molecules, SO3 only has weak van der waals intermolecular forces holding its molecules together. Since covalent bonds require more energy to overcome than van der waals, SiO2 requires a higher temperature than SO3 to melt, thus SiO2 has a higher melting point.
Answer:
Numbers of electrons transferred in the electrolytic or voltaic cell is 6 electrons.
Explanation:
![Fe^{3+} (aq) + 3 e^-\rightarrow Fe (s) ,E^o = -0.036 V](https://tex.z-dn.net/?f=Fe%5E%7B3%2B%7D%20%28aq%29%20%2B%203%20e%5E-%5Crightarrow%20Fe%20%28s%29%20%2CE%5Eo%20%3D%20-0.036%20V)
![Mg^{2+}(aq) + 2 e^- \rightarrow Mg (s),E^o = -2.37 V](https://tex.z-dn.net/?f=Mg%5E%7B2%2B%7D%28aq%29%20%2B%202%20e%5E-%20%5Crightarrow%20Mg%20%28s%29%2CE%5Eo%20%3D%20-2.37%20V)
The substance having highest positive reduction
potential will always get reduced and will undergo reduction reaction.
Reduction : cathode
..[1]
Oxidation: anode
..[2]
Oxidation reaction occurs at anode and reduction reaction occurs at cathode.
To calculate the
of the reaction, we use the equation:
![E^o_{cell}=E^o_{red,cathode}-E^o_{red,anode}](https://tex.z-dn.net/?f=E%5Eo_%7Bcell%7D%3DE%5Eo_%7Bred%2Ccathode%7D-E%5Eo_%7Bred%2Canode%7D)
![E^o_{cell}=-0.036V-(-2.37 V)=2.334 V](https://tex.z-dn.net/?f=E%5Eo_%7Bcell%7D%3D-0.036V-%28-2.37%20V%29%3D2.334%20V)
The overall reaction will be:
2 × [1] + 3 × [2] :
![2Fe^{3+} (aq) + 3Mg(s)+6e^-\rightarrow 2Fe (s)+3Mg^{2+}(aq)+6e^-](https://tex.z-dn.net/?f=2Fe%5E%7B3%2B%7D%20%28aq%29%20%2B%203Mg%28s%29%2B6e%5E-%5Crightarrow%202Fe%20%28s%29%2B3Mg%5E%7B2%2B%7D%28aq%29%2B6e%5E-)
Electrons on both sides will get cancelled :
![2Fe^{3+} (aq) + 3Mg(s)\rightarrow 2Fe (s)+3Mg^{2+}(aq)](https://tex.z-dn.net/?f=2Fe%5E%7B3%2B%7D%20%28aq%29%20%2B%203Mg%28s%29%5Crightarrow%202Fe%20%28s%29%2B3Mg%5E%7B2%2B%7D%28aq%29)
Numbers of electrons transferred in the electrolytic or voltaic cell is 6 electrons.
Answer:
B. Ca(NO2)2
Explanation:
Ions (charged atoms) combine with one another to form stable ionic compounds. In this case, calicium ion (Ca2+) is said to react with NO2, which has a charge of -1 i.e. +1-1(2) = 1-2 = -1.
This means that calcium has a charge of +2 while nitrite ion has charge of -1, hence, when they combine, they exchange their charges, which become their subscript as follows:
Ca2+ + NO2- → Ca(NO2)2
Ca(NO2)2 is a stable ionic compound called calcium nitrite. Notice that it takes two atoms of NO2- to react with one atom of Ca2+.
<span>The form of energy related to measurement of kinetic energy is heat energy. Basically, thermal energy is related to the measurement of molecula kinetics of a substance. It is due to the thermoagitation of the partices of the substances, which keep on moving. </span>