Answer:
1.1 percent
Explanation:
C6H5COOH⇌C6H5COO+H
Ka = [C6H5COO-][H+]/[C6H5COOH]
From pKa of 4.2, Ka = 6.3x10^-5
6.3x10^-5 = (x)(x)/0.51-x and assuming x is small...
6.3x10^-5 = x^2/0.51
x^2 = 3.213x10^-5
x =5.67 x10^-3
(5.67x10^-3/0.51)x 100 =1.1 percent
Answer:
see explanation and punch in the numbers yourself ( will be better for your test)
Explanation:
If you are given atoms you need to divide by Avogadro's number 6.022x10^23
then you will have moles of sulfur-- once you have moles multiply by the molar mass of sulfur to go from moles to grams
mm of sulfur is 32 g/mol
This problem is describe the mole-ratio composition of an allow composed by tin, lead and cadmium. Ratios are given as Sn:Pb 2.73:1.00 and Pb:Cd is 1.78:1.00, and we are asked to calculate the mass percent compositon of Pb in the allow.
In this case, according to the given information, it turns out possible realize that the following number of moles are present in the alloy, according to the aforementioned ratios:
Next, we calculate the masses by using each metal's atomic mass:
Thus, the mass percent composition of each metal is shown below:
So that of lead is 34.9 %.
Learn more:
A mixture can be separated by looking at the physical properties of the components of the mixture.
Since salt is soluble in water, it can be added to the mixture to dissolve the salt.
The bar magnet is now introduced in order to remove the iron filings since they are attracted by a magnet.
The solution is filtered to separate the sand from the salt solution.
Lastly, the salt solution is heated to dryness to drive away the water and obtain the solid salt.
Hence the mixture has been separated into its components using their individual physical properties. Option A is the correct answer.
Learn more: brainly.com/question/12160179
6.023*1023 He atoms=1 mole He
1.23×1024 helium atoms=1.23×1024/6.023*1023 =2.042 mole He
one mole He=4.0 gm
2.042 mole He=2.042*4.0=8.168 gm
answer in grams of Helium is 8.168 gm
