Chemical properties of matter can only be observed and measured by performing a chemical change.
- Density and boiling are not chemical changes.
- This leaves reactivity and combustion. Reactivity does not need to be observed at STP so the statement is wrong.
Combustion is the best answer.
One thing incorrect is that when dealing with a compound, such as H2SO4, that has 7 atoms in the chemical formula, the polyatomic ion SO4 doesn’t dissociate into one Sulfur and four Oxygens. SO4 stays and a PAI.
The ion charge of this element, Na would be + 1, as a single valence electron has been removed and transferred to another atom, resulting in an atom with a greater number of protons than electrons, making it positively charged.
Answer:
H + ions are attracted to the cathode , gain electrons and form hydrogen gas. OH - ions are attracted to the anode , lose electrons and form oxygen gas.
Answer:
Rate of reaction =
Rate of consumption of A = 
Rate of consumption of B =
Rate of formation of D = 
Explanation:
According to laws of mass action for the given reaction,
![Rate= -\frac{1}{2}\frac{\Delta [A]}{\Delta t}=-\frac{\Delta [B]}{\Delta t}=\frac{1}{2}\frac{\Delta [C]}{\Delta t}=\frac{1}{3}\frac{\Delta [D]}{\Delta t}](https://tex.z-dn.net/?f=Rate%3D%20-%5Cfrac%7B1%7D%7B2%7D%5Cfrac%7B%5CDelta%20%5BA%5D%7D%7B%5CDelta%20t%7D%3D-%5Cfrac%7B%5CDelta%20%5BB%5D%7D%7B%5CDelta%20t%7D%3D%5Cfrac%7B1%7D%7B2%7D%5Cfrac%7B%5CDelta%20%5BC%5D%7D%7B%5CDelta%20t%7D%3D%5Cfrac%7B1%7D%7B3%7D%5Cfrac%7B%5CDelta%20%5BD%5D%7D%7B%5CDelta%20t%7D)
where, ![-\frac{\Delta [A]}{\Delta t}](https://tex.z-dn.net/?f=-%5Cfrac%7B%5CDelta%20%5BA%5D%7D%7B%5CDelta%20t%7D)
is rate of consumption of A, ![-\frac{\Delta [B]}{\Delta t}](https://tex.z-dn.net/?f=-%5Cfrac%7B%5CDelta%20%5BB%5D%7D%7B%5CDelta%20t%7D)
is rate of consumption of B, ![\frac{\Delta [C]}{\Delta t}](https://tex.z-dn.net/?f=%5Cfrac%7B%5CDelta%20%5BC%5D%7D%7B%5CDelta%20t%7D)
is rate of formation of C and ![\frac{\Delta [D]}{\Delta t}](https://tex.z-dn.net/?f=%5Cfrac%7B%5CDelta%20%5BD%5D%7D%7B%5CDelta%20t%7D)
is rate of formation of D
Here ![\frac{\Delta [C]}{\Delta t}=2.7mol.dm^{-3}.s^{-1}](https://tex.z-dn.net/?f=%5Cfrac%7B%5CDelta%20%5BC%5D%7D%7B%5CDelta%20t%7D%3D2.7mol.dm%5E%7B-3%7D.s%5E%7B-1%7D)
So, Rate of reaction = 
Rate of formation of D = ![(\frac{3}{2}\times \frac{\Delta [C]}{\Delta t})=(\frac{3}{2}\times 2.7mol.dm^{-3}.s^{-1})=4.15mol.dm^{-3}.s^{-1}](https://tex.z-dn.net/?f=%28%5Cfrac%7B3%7D%7B2%7D%5Ctimes%20%5Cfrac%7B%5CDelta%20%5BC%5D%7D%7B%5CDelta%20t%7D%29%3D%28%5Cfrac%7B3%7D%7B2%7D%5Ctimes%202.7mol.dm%5E%7B-3%7D.s%5E%7B-1%7D%29%3D4.15mol.dm%5E%7B-3%7D.s%5E%7B-1%7D)
Rate of consumption of A = ![(\frac{2}{2}\times \frac{\Delta [C]}{\Delta t})=(\frac{2}{2}\times 2.7mol.dm^{-3}.s^{-1})=2.7mol.dm^{-3}.s^{-1}](https://tex.z-dn.net/?f=%28%5Cfrac%7B2%7D%7B2%7D%5Ctimes%20%5Cfrac%7B%5CDelta%20%5BC%5D%7D%7B%5CDelta%20t%7D%29%3D%28%5Cfrac%7B2%7D%7B2%7D%5Ctimes%202.7mol.dm%5E%7B-3%7D.s%5E%7B-1%7D%29%3D2.7mol.dm%5E%7B-3%7D.s%5E%7B-1%7D)
Rate of consumption of B = ![(\frac{1}{2}\times \frac{\Delta [C]}{\Delta t})=(\frac{1}{2}\times 2.7mol.dm^{-3}.s^{-1})=1.35mol.dm^{-3}.s^{-1}](https://tex.z-dn.net/?f=%28%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5Cfrac%7B%5CDelta%20%5BC%5D%7D%7B%5CDelta%20t%7D%29%3D%28%5Cfrac%7B1%7D%7B2%7D%5Ctimes%202.7mol.dm%5E%7B-3%7D.s%5E%7B-1%7D%29%3D1.35mol.dm%5E%7B-3%7D.s%5E%7B-1%7D)
