Answer:
29.3 g HClO₄
Explanation:
We have 39.1 grams of 74.9 wt% aqueous perchloric acid solution, that is, there are 74.9 grams of perchloric acid in 100 grams of perchloric acid solution. The mass, in grams, of perchloric acid contained in 39.1 grams of perchloric acid solution is:
39.1 g Solution × (74.9 g HClO₄/100 g Solution) = 29.3 g HClO₄
1s^2
2s^2
2p^6
3s^2
3p^6
4s^2
3d^10
4p^4
1) 0.89% m/v = 0.89 grams of NaCl / 100 ml of solution
=> 8.9 grams of NaCl in 1000 ml of solution = 8.9 grams of NaCl in 1 liter of solution
2) Molarity = M = number of moles of solute / liters of solution
=> calculate the number of moles of 8.9 grams of NaCl
3) molar mass of NaCl = 23.0 g /mol + 35.5 g/mol = 58.5 g / mol
4) number of moles of NaCl = mass / molar mass = 8.9 g / 58.5 g / mol = 0.152 mol
5) M = 0.152 mol NaCl / 1 liter solution = 0.152 M
Answer: 0.152 M
The molecular weight of hemoglobin can be calculated using osmotic pressure
Osmotic pressure is a colligative property and it depends on molarity as
πV = nRT
where
π = osmotic pressure
V = volume = 1mL = 0.001 L
n = moles
R = gas constant = 0.0821 L atm / mol K
T = temperature = 25°C = 25 + 273 K = 298 K
Putting values we will get value of moles
![moles=\frac{\pi V}{RT}=\frac{0.00195X0.001}{0.0821X298}mol](https://tex.z-dn.net/?f=moles%3D%5Cfrac%7B%5Cpi%20V%7D%7BRT%7D%3D%5Cfrac%7B0.00195X0.001%7D%7B0.0821X298%7Dmol)
we know that
![moles=\frac{mass}{molarmass}](https://tex.z-dn.net/?f=moles%3D%5Cfrac%7Bmass%7D%7Bmolarmass%7D)
Therefore
![molarmass=\frac{mass}{moles}=\frac{5.10X10^{-3}g}{7.97X10^{-8}}=6.399X10^{4}g](https://tex.z-dn.net/?f=molarmass%3D%5Cfrac%7Bmass%7D%7Bmoles%7D%3D%5Cfrac%7B5.10X10%5E%7B-3%7Dg%7D%7B7.97X10%5E%7B-8%7D%7D%3D6.399X10%5E%7B4%7Dg)
Potassium is not found free in nature but is found in the form of potash. Potash is the ore of potassium and this ore is mined from deep down the earth or can sometimes be found on the surface. Potash was mostly formed as sea water receded and left deposits.
Potash is usually in the form of potassium salts such potassium chloride and potassium sulphate. The potash is mined then taken to the factory where it is crushed and purified by removing such impurities as clay.
The now purified potassium salts are subjected to a process called electrolysis where potassium metal is obtained from its salt.