Answer:
The electrons that occupy the outermost shell of an atom are called valence electrons. Valence electrons are important because they determine how an atom will react. By writing an electron configuration, you'll be able to see how many electrons occupy the highest energy level .
Answer:
The final temperature is:- 7428571463.57 °C
Explanation:
The expression for the calculation of heat is shown below as:-
Where,
is the heat absorbed/released
m is the mass
C is the specific heat capacity
is the temperature change
Thus, given that:-
Mass of water = 1.75 mg = 0.00175 g ( 1 g = 0.001 mg)
Specific heat of water = 4.18 J/g°C
Initial temperature = 35 °C
Final temperature = x °C
kcal
Also, 1 kcal = 4.18 kJ = J
So, Q = J = 54340000 J
So,
Thus, the final temperature is:- 7428571463.57 °C
Answer:
43.89 min
Explanation:
Given that:-
The speed of light =
The distance =
The conversion of distance in km to distance into m is shown below as:-
1 km = 1000 m
So,
Distance =
The relation between speed distance and time is shown below as:-
Thus,
Time = 2633.33 seconds
Also, 1 s = 1/60 min
So,
Time=
Answer:
The standard enthalpy of formation of NOCl(g) at 25 ºC is 105 kJ/mol
Explanation:
The ∆H (heat of reaction) of the combustion reaction is the heat that accompanies the entire reaction. For its calculation you must make the total sum of all the heats of the products and of the reagents affected by their stoichiometric coefficient (number of molecules of each compound that participates in the reaction) and finally subtract them:
Enthalpy of the reaction= ΔH = ∑Hproducts - ∑Hreactants
In this case, you have: 2 NOCl(g) → 2 NO(g) + Cl₂(g)
So, ΔH=
Knowing:
- ΔH= 75.5 kJ/mol
- = 90.25 kJ/mol
- = 0 (For the formation of one mole of a pure element the heat of formation is 0, in this caseyou have as a pure compound the chlorine Cl₂)
- =?
Replacing:
75.5 kJ/mol=2* 90.25 kJ/mol + 0 -
Solving
-=75.5 kJ/mol - 2*90.25 kJ/mol
-=-105 kJ/mol
=105 kJ/mol
<u><em>The standard enthalpy of formation of NOCl(g) at 25 ºC is 105 kJ/mol</em></u>