Answer:
5.72 g ( 1 mol / 180.16 g ) ( 6.022 x 10^23 molecules / mole ) = 1.90x10^23 molecules
Plz help me I need help to but in math plzz I have 2 miplz help me
Answer:
ΔH = +26.08 kJ/mol
Explanation:
The change in enthalpy (ΔH) is given in J/mol, and can be calculated for dissolution by the equation:
ΔH = m(water)*Cp*ΔT/n(solute)
The mass of water is the density multiplied by the volume
m = 1g/mL * 25.0mL = 25.0 g
The number of the moles is the mass divided by the molar mass. Knowing the molar masses of the elements:
N = 14 g/mol x 2 = 28
H = 1 g/mol x 4 = 4
O = 16 g/mol x 3 = 48
NH₄NO₃ = 80 g/mol
n = 1.25/80 = 0.015625 mol
So,
ΔH = 25*4.18*(25.8 - 21.9)/0.015625
ΔH = 26,083.2 J/mol
ΔH = +26.08 kJ/mol
Answer: A
Explanation: A, because when you eat it is you use chemical energy afterward you run and use mechanical energy. Ex of Chemical energy can be batteries and you digesting food. Mechanical is movement.
The given chemical reaction is:
The standard heats of formation of 
are:
Δ
) = -285.8kJ/mol[/tex]
Δ
) = -187.6 kJ/mol[/tex]
Calculating the change in heat:
Δ
=∑ΔH
-∑ΔH
= [{2 * (-285.8 kJ/mol)} -{2*(-187.6 kJ/mol)}]
= -196.4 kJ/mol
Therefore, the change in enthalpy for the given reaction is -196.4 kJ/mol
