Explanation:
Percentage ethylene by weight = 57%
Percentage propylene by weight = 43%
Suppose in 100 grams of polymer:
Mass of ethylene = 57 g
Mass of propylene = 43 g
Moles of ethylene = ![\frac{57 g}{28 g/mol}=2.036 mol](https://tex.z-dn.net/?f=%5Cfrac%7B57%20g%7D%7B28%20g%2Fmol%7D%3D2.036%20mol)
Moles of propylene = ![\frac{43g}{42g/mol}=1.024 mol](https://tex.z-dn.net/?f=%5Cfrac%7B43g%7D%7B42g%2Fmol%7D%3D1.024%20mol)
1 mole =
molecules/ atoms
Units of ethylene = ![2.036 mol\times N_A](https://tex.z-dn.net/?f=2.036%20mol%5Ctimes%20N_A)
Units of propylene = ![1.024 mol\times N_A](https://tex.z-dn.net/?f=1.024%20mol%5Ctimes%20N_A)
a) Fraction of ethylene units:
![=\frac{2.036 mol\times N_A}{2.306 mol\times N_A+1.024 mol\times N_A}=\frac{509}{765}](https://tex.z-dn.net/?f=%3D%5Cfrac%7B2.036%20mol%5Ctimes%20N_A%7D%7B2.306%20mol%5Ctimes%20N_A%2B1.024%20mol%5Ctimes%20N_A%7D%3D%5Cfrac%7B509%7D%7B765%7D)
b ) Fraction of propylene units:
![=\frac{1.024mol\times N_A}{2.306 mol\times N_A+1.024 mol\times N_A}=\frac{256}{765}](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1.024mol%5Ctimes%20N_A%7D%7B2.306%20mol%5Ctimes%20N_A%2B1.024%20mol%5Ctimes%20N_A%7D%3D%5Cfrac%7B256%7D%7B765%7D)
The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.
<span>Which of the following is an electronic device that measures pH?
</span><span>a. a pH meter</span>
Answer:
A
Explanation:
Element A has 3 electrons in outermost shell so its valency is 3. It will loose 3 electrons to attain stability, as loss of 3 electrons is easier than gain of 5 electrons.
Valency of B is −2 as it will gain 2 electrons to attain stability and combine with other atom.
Valency of A⟶+3
Valency of B⟶−2
(Refer to Image)
Cross multiply valency of A and B
∴A2B3 compound will be formed.