An aqueous solution in a 55 gallon (208 l drum), characterized by minimal buffering capacity, received 4kg of phenol and 1.5 kg of sodium phenate. What is the ph of the solution. The pka of phenol = 9.98. Mw of phenol and sodium phenate are 94 g/mol and 116 g/mol, respectively.
Volume of solution = 55 gallons = 208.2 L [ 1 gallon = 3.78 L]
moles of phenol = mass / molar mass = 4000 g / 94 = 42.55 moles
moles of sodium phenate = mass / molar mass = 1500 / 116 = 12.93 moles
pKa of phenol = 9.98
We know that the pH of buffer is calculated using Hendersen Hassalbalch's equation
pH = pKa + log [salt] / [acid]
volume is same for both the sodium phenate and phenol has we can directly take the moles of each in the formula
pH = 9.98 + log [12.93 / 42.55] = 9.46
Answer: When the air particles inside the balloon become colder, they slow down and do not hit the inside of the balloon as often, so the balloon's volume decreases.
There are several scales to determine the weight of material. The chose of the weight scale depends upon the size of the material. Like if we have to measure the molecular or atomic weight of a molecule or atom we use gm. Like that for the bigger molecules like proteins the weight of the molecule is expressed by different scale due to its big size. Like that for big material like iron rods etc we generally use kilograms or ton. There are two types of measuring units one is C.G.S. and another is S.I. The S.I. units are more acceptable worldwide than that the C.G.S. units as the digit comes in SI units are easily handable than that of CGS.
Thus metric is used to determine a large weight of compounds which is a SI unit and handable.
Answer:
Ionic compounds have a metal and nonmetal.
Ionic compounds are made up of ions.
Explanation:
You did not provide any formulas for me to correct, but:
- ionic compounds tend to have metals and nonmetals. (EX: NaCl)You can look at the periodic table to see which elements are metals and which are not.
- ionic compounds are made up of ions. Ions are elements that have a charge (Like
or 
). To have a correct ionic compound, make sure that the ions inside of it "cancel" each other out.
EX: Na has a +1 charge. Cl has a -1 charge. When they are paired up, they successfully cancel each other out (become neutral) and become the ionic compound NaCl.
The chart below shows you the charge of each element. Make sure the charge of the elements in an ionic compound "cancel" each other out.
The very last chart shows the metals and nonmetals
Chart 1:found in https://chem.libretexts.org/Courses/Oregon_Tech_PortlandMetro_Campus/OT_-_PDX_-_Metro%3A_General_Chemistry_I/03%3A_Nuclei_Ions_and_the_Periodic_Table/3.03%3A_Predicting_Charges_of_Ions
Chart 2: found in https://sciencenotes.org/metals-metalloids-nonmetals/
Answer:
1720.8g water are necessaries
Explanation:
Mass percent is defined as the mass of solute (In this case, MgCl2) in 100g of solution (Mass MgCl2 + Mass water). To solve this question we must find the mass of solution that we need to produce th 1.5% by mass solution. Thus, we can find the mass of water that we need as follows:
<em>Mass solution:</em>
26.2g MgCl2 * (100g Solution / 1.5g MgCl2) = 1747g solution
<em>Mass water:</em>
1747g solution - 26.2g MgCl2 = 1720.8g water are necessaries
