Answer:
A simple displacement reaction occurs when an iron nail is immersed to a beaker containing copper sulphate solution.
a)
Iron is more reactive than copper. As a result a displacement reaction will take place. The ferrous or Fe (II) irons will move to the solution. The copper ions (Cu II) will get deposited on the nail. This will cause the colour to change from blue to green.
b)
The equation can be written as:
Fe (s) + CuSO4 (aq) -> FeSO4 (aq) + Cu (s)
c)
A chemical change can be described as a change that causes a substance to change to another form. Hence, this reaction is a chemical change.
<span>1.15x10^24 molecules of hypothetical substance b
Making the assumption that each molecule in hypothetical substance a reacts to produce a single molecule of hypothetical substance b, then the number of molecules of substance b will be the number of moles of substance a multiplied by avogadro's number. So
Moles hypothetical substance a = 29.9 g / 15.7 g/mol = 1.904458599 moles
This means that we should also have 1.904458599 moles of hypothetical substance b. And to get the number of atoms, multiply by 6.0221409x10^23, so:
1.904458599 * 6.0221409x10^23 = 1.146892x10^24 molecules.
Rounding to 3 significant figures gives 1.15x10^24</span>
I think it 2.25 or somethingg
You can use the follwing equations.
pH=14-pOH
pOH=-log[OH⁻]
a) pOH=-log10⁻¹²
pOH=12
pH=14-12
pH=2
You can also use these equations:
[H⁺]=K(w)/[OH⁻] (K(w)=1.01×10⁻¹⁴)
pH=-log[H⁺]
b) [H⁺]=(1.01×10⁻¹⁴)/10⁻²M
[H⁺]=1.01×10⁻¹²M²
pH=-log(1.01×10⁻¹²)
pH=12
You can use either method. It does not really matter.
I hope this helps. Let me know if anything is unclear and when you do the calculations for c you should get pH=7.
