Answer:
C 1:1
Explanation:
Hydrogen loses an electron to becone +1 which is a cation and flourine gains that electron to have a full outer shell on the 2p subshell to become -1 and is an anion so the ratio is 1:1.
The pH of pure water has been best described as neutral pH with equal hydronium and hydroxide ions. Thus, option A is correct.
pH has been described as the measurement of hydrogen ions in a solution. The pH has been measured on a scale of 1-14. pH 7 has been the neutral pH.
The higher hydronium ion concentration tends to move the pH from 7 towards 1. The higher hydroxide ion concentration tends to move the pH above 7.
The neutral pH has been neither acidic nor basic with the equal constituents of hydronium and hydroxide ion in the solution.
Thus, the pH of pure water has been 7. It has neutral pH with equal hydronium and hydroxide ions. Thus, option A is correct.
For more information about the pH of the solution, refer to the link:
brainly.com/question/4975103
1.59moles
Explanation:
Mass of CaO = 89.23g
Unknown
Number of moles = ?
Solution:
The mole is a unit of measurement in chemistry used to delineate the number of particles an atom contains.
A mole of a substance contains the avogadro's number of particles.
Number of moles = 
Molar mass of CaO = 40 + 16 = 56g/mol
Number of moles =
= 1.59moles
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Number of moles brainly.com/question/1841136
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Trace fossils provide us with indirect evidence of life in the past, such as the footprints, tracks, burrows, borings, and feces left behind by animals, rather than the preserved remains of the body of the actual animal itself. so i would say B.
Answer : The molar heat of solution of KCl is, 17.19 kJ/mol
Explanation :
First we have to calculate the heat of solution.

where,
q = heat produced = ?
c = specific heat capacity of water = 
= change in temperature = 0.360 K
Now put all the given values in the above formula, we get:


Now we have to calculate the molar heat solution of KCl.

where,
= enthalpy change = ?
q = heat released = 460.8 J
m = mass of
= 2.00 g
Molar mass of
= 74.55 g/mol

Now put all the given values in the above formula, we get:


Therefore, the molar heat of solution of KCl is, 17.19 kJ/mol