6.8 is the pH of the solution after 10 ml of 5M NaOH is added.
Explanation:
Data given:
Molarity of C6H5CCOH = 0.100 M
molarity of ca(c6h5coo)2 = 0.2 M
Ka = 6.3 x 10^-5
first pH is calculated of the buffer solution
pH = pKa+ log 10 ![\frac{[A-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA-%5D%7D%7B%5BHA%5D%7D)
pKa = -log10[Ka]
pka = -log[6.3 x10^-5]
pKa = 4.200
putting the values to know pH of the buffer
pH = 4.200 + log 10 
pH = 4.200 + 0.3
pH = 4.5 (when NaOH was not added, this is pH of buffer solution)
now the molarity of the solution is calculated after NaOH i.e Mbuffer is added
MbufferVbuffer = Mbase Vbase
putting the values in above equation:
Mbuffer = 
= 
= 0.01 M
molarity or [ A-] = 5M
pH = pKa+ log 10
pH = 4.200 + log 10 
pH = 4.200+ 2.69
pH = 6.8
I think the correct answer from the choices listed above is the last option. The family that contains disinfectants is the halogens. This group includes the elements fluorine, chlorine, bromine, iodine, and astatine. Disinfectants are chemical agents that inhibit or kill microorganisms on inanimate objects.
Answer. One of the key components of the softgel capsule is the plasticizer used to make the shell elastic and pliable and to minimize brittleness and cracking. The plasticizer usually accounts for 20-30% of the wet gel formulation which can impact the quality of the finished product.
Explanation:
B is the correct answer if I remember
Answer:
A. 0.2395 w/w %
B. 2394ppm
Explanation:
A. To find concentrationin percent by mass of the solution we need to calculate mass of glycerol and mass of water. The formula is:
Mass glycerol / Total mass * 100
<em>Mass glycerol:</em>
The solution is 2.6x10⁻²moles / L. As there is 1L of solution there are 2.6x10⁻² moles of glycerol. In mass (Using molar mass glycerol: 92.09g/mol):
2.6x10⁻² moles of glycerol * (92.09g / mol) = 2.394g glycerol
<em>Mass of water:</em>
998.9mL and density = 0.9982g/mL:
998.9mL * (0.9982g/mL) = 997.1g of water.
That means percent by mass is:
% by mass: 2.394g / (997.1g + 2.394g) * 100 = 0.2395 w/w %
B. Parts per million are mg of glycerol per L of solution. As in 1L there are 2.394g. In mg:
2.394g * (1000mg / 1g) = 2394mg:
Parts per million: 2394mg / L = 2394ppm
