Characteristic ions of water: OH- and H3O+
1 answer:
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Answer:
The total change in enthalpy for the reaction is - 81533.6 J/mol
Explanation:
Given the data in the question;
Reaction;
HCl + NaOH → NaCl + H₂O
Where initial temperature is 21.2 °C and final temperature is 28.0 °C. Ccal is 1234.28 J
Moles of NaOH = 50.mL × 1.00 M = 50.0 mmol = 0.0500 mol
Moles of HCl = 50.mL × 1.00 M = 50.0 mmol = 0.0500 mol
so, 0.0500 moles of H₂O produced
Volume of solution = 50.mL + 50.mL = 100.0 mL
Mass of solution m = volume × density = 100.0mL × 1.0 g/mL = 100 g
now ,
Heat energy of Solution q= (mass × specific heat capacity × temp Δ) + Cal
we know that; The specific heat of water(H₂O) is 4.18 J/g°C.
so we substitute
q_soln = (100g × 4.18 × ( 28.0 °C - 21.2 °C) ) + 1234.28
q_soln = 2842.4 + 1234.28
q_soln = 4076.68 J
Enthalpy change for the neutralization is ΔH
ΔH = -q_soln / mole of water produced
so we substitute
ΔH = -( 4076.68 J ) / 0.0500 mol
ΔH = - 81533.6 J/mol
Therefore, the total change in enthalpy for the reaction is - 81533.6 J/mol
Answer:
See the images below
Step-by-step explanation:
To draw a dot diagram of an atom, you locate the element in the Periodic Table and figure out how many valence electrons it has. Then you distribute the electrons as dots around the atom,
a. Silicon.
Si is in Group 14, so it has four valence electrons.
b. Xenon
Xenon is in Group 18, so it has eight valence electrons. We group them as four pairs around the xenon atom.
c. Calcium
Calcium is in Group 2, so it has two valence electrons. They are in a single subshell, so we write them as a pair on the calcium atom.
d. Water
Oxygen is in Group 16, so it has six valence electrons. The hydrogen atoms each contribute one electron, so there are eight valence electrons.
Chemists often use a dash to represent a pair of electrons in a bond.
