The pH value can be measured using electrochemical measuring systems, litmus paper, or indicators and colorimeters. The easiest way to take a pH measurement is to use litmus paper or a colorimeter. The advantage of this type of pH measurement is that the pH range is well known and they are easy to apply.
1. Answer;
=56 g/mol
Explanation and solution;
PV = nRT
nRT= mass/molar mass (RT)
molar mass = (mass/V ) × (RT/P)
= Density × (RT/P)
Molar mass = 2.0 g/L × (0.0821 × 323 K)/0.948 atm
Molar mass = 56 g/mol
2. Answer;
Molecular mass is C4H8
Explanation;
Empirical mass × n = molar mass
Empirical mass for CH2 = 14 g/mol
Therefore;
56 g/mol = 14 g/mol × n
n = 4
The molecular formula= 4(CH2)
= C4H8
Explanation:
The chemical equation is as follows.

And, the given enthalpy is as follows.
;
= 102.5 kJ
Cl-Cl = 243 kJ/mol, O=O = 498 kJ/mol
Since, the bond enthalpy of Cl-Cl is not given so at first, we will calculate the value of Cl-Cl as follows.
102.5 = ![[(\frac{1}{2})x + 498] - [(2)(243)]](https://tex.z-dn.net/?f=%5B%28%5Cfrac%7B1%7D%7B2%7D%29x%20%2B%20498%5D%20-%20%5B%282%29%28243%29%5D)
102.5 = 
102.5 - 12 = 
x = 181 kJ
Now, total bond enthalpy of per mole of ClO is calculated as follows.

x = ![[(\frac{1}{2})181 + (\frac{1}{2})498] - 243](https://tex.z-dn.net/?f=%5B%28%5Cfrac%7B1%7D%7B2%7D%29181%20%2B%20%28%5Cfrac%7B1%7D%7B2%7D%29498%5D%20-%20243)
= 339.5 - 243
= 96.5 kJ
Thus, we can conclude that the value for the enthalpy of formation per mole of ClO(g) is 96.5 kJ.
Answer:
Explanation:
Answer 1:
Lithium : 1s2 2s1 Fluorine: 1s2 2s2 2p5 Carbon: 1s2 2s2 2p2
Argon : 1s2 2s2 2p6 3s2 3p6 Sulphur: 1s2 2s2 2p6 3s2 3p4
Nickel: 1s2 2s2 2p6 3s2 3p6 3d8 4s2 Rubidium: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s1 Xenon: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6
Answer 2: A. Fluorine B. Calcium
C. It is Tellurium if this was the exact electronic configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p4 you intend to write, if not, no element has such electonic configuration.
D. Bromine but the correct electronic configuration is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p5
The percent composition of each element can be calculated as follows:
% composition = (mass of element / total mass) * 100
The total mass of the quarter is given to be 5.670 grams
Mass of Cu = 5.198 grams
Mass of Ni = 0.472 grams
Substitute in the above equation to get the mass percentage of each element as follows:
% of Cu = (5.198/5.670) * 100 = 91.675%
% of Ni = (0.472/5.670) * 100 = 8.325%