Answer:
pH=10.97
Explanation:
the solution of methyl amine with methylammonium chloride will make a buffer solution.
The pH of buffer solution can be obtained using Henderson Hassalbalch's equation, which is:
![pOH=pKb+log\frac{[salt]}{[base]}](https://tex.z-dn.net/?f=pOH%3DpKb%2Blog%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bbase%5D%7D)
pH = 14- pOH
Let us calculate pOH
[Salt] = [methylammonium chloride] = 0.10 M (initial)
After adding base
![[salt] = \frac{molarityXvolume}{finalvolume}=\frac{0.1X20}{(20+50)}= 0.0286M](https://tex.z-dn.net/?f=%5Bsalt%5D%20%3D%20%5Cfrac%7BmolarityXvolume%7D%7Bfinalvolume%7D%3D%5Cfrac%7B0.1X20%7D%7B%2820%2B50%29%7D%3D%200.0286M)
[base] = [Methylamine]=0.10
After mixing with salt
![[base]= \frac{molarityXvolume}{finalvolume}=\frac{0.1X50}{(20+50)}= 0.0714M](https://tex.z-dn.net/?f=%5Bbase%5D%3D%20%5Cfrac%7BmolarityXvolume%7D%7Bfinalvolume%7D%3D%5Cfrac%7B0.1X50%7D%7B%2820%2B50%29%7D%3D%200.0714M)
pKb= -log[Kb]= 3.43
Putting values
pOH = ![3.43+log(\frac{[0.0286]}{0.0714}](https://tex.z-dn.net/?f=3.43%2Blog%28%5Cfrac%7B%5B0.0286%5D%7D%7B0.0714%7D)
Answer:
[HClO₄] = 11.7M
Explanation:
First of all we need to know, that a weight percent represents, the mass of solute in 100 g of solution.
Let's convert the mass to moles → 70.5 g . 1mol/100.45 g = 0.702 moles
Now we can apply the density to calculate the volume.
Density always refers to solution → Solution density = Solution mass / Solution volume
1.67 g/mL = 100 g / Solution volume
Solution volume = 100 g / 1.67 g/mL → 59.8 mL
To determine molarity (mol/L) we must convert the mL to L
59.8 mL . 1L/1000mL = 0.0598 L
Molarity → Moles of solute in 1L of solution → 0.702 mol / 0.0598 L = 11.7M
<span>At standard temperature and pressure 22.4 l of an ideal gas would contain 1 mole. in order to find the change in moles we must look at the ideal gas law PV=nRT where P=Pressure V=volume n=Moles R= Gas constant T= Temperature. To simplify this equation we will be using the gas constant at .08206 L-atm/mol-K. We must first convert 100c to k which is 373.15. Then we can plug the values into our equation which gives us (2atm)(14.5 l)=(n)(.08206 L-atm/mol-K)(373.15). After some basic algebra we get the moles to equal roughly .95 which is .05 moles less than our original system.</span>
The element with the nlx notation of 5d2 in the periodic table is hafnium with a symbol of hf. It is a chemical element and has an atomic number 72. H<span>afnium chemically resembles zirconium and is found in many zirconium minerals but it is a complete contrast of zirconium which is also chemically similar to hafnium.</span>
3 Mg + 1 Fe2O3 →2 Fe + 3MgO
Type of Reaction: Single displacement.
