Answer:
0.583 kilojoules
Explanation:
The amount of heat required to pop a single kernel can be calculated using the formula as follows:
Q = m × c × ∆T
Where;
Q = amount of heat (J)
m = mass of water (g)
c = specific heat capacity of water (4.184 J/g°C)
∆T = change in temperature
From the given information, m = 0.905 g, initial temperature (room temperature) = 21°C , final temperature = 175°C, Q = ?
Q = m × c × ∆T
Q = 0.905 × 4.184 × (175°C - 21°C)
Q = 3.786 × 154
Q = 583.044 Joules
In kilojoules i.e. we divide by 1000, the amount of heat is:
= 583.04/1000
= 0.583 kilojoules
Did you mean the atomic mass?
Missing data in your question: (please check the attached photo)
from this balanced equation:
M(OH)2(s) ↔ M2+(aq) + 2OH-(aq) and when we have Ksp = 2x10^-16
∴Ksp = [M2+][OH]^2
2x10^-16 = [M2+][OH]^2
a) SO at PH = 7 ∴POH = 14-PH = 14- 7 = 7
when POH = -㏒[OH]
7= -㏒[OH]
∴[OH] = 1x10^-7 m by substitution with this value in the Ksp formula,
∴[M2+] =Ksp /[OH]^2
= (2x10^-16)/(1x10^-7)^2
= 0.02 M
b) at PH =10when POH = 14- PH = 14-10 = 4
when POH = -㏒[OH-]
4 = -㏒[OH-]
∴[OH] = 1x10^-4 ,by substitution with this value in the Ksp formula
[M2+] = Ksp/ [OH]^2
= 2x10^-16 / (1x10^-4)^2
= 2x10^-8 Mc) at PH= 14
when POH = 14-PH
= 14 - 14
= 0
when POH = -㏒[OH]
0 = - ㏒[OH]
∴[OH] = 1 m
by substitution with this value in Ksp formula :
[M2+] = Ksp / [OH]^2
= (2x10^-16) / 1^2
= 2x10^-16 M
The Avogadro number represents the number of units in one mole of a chemical substance.
So to find the mole number of a chemical element, you divide its atom number of the Avogadro number which Na = 6.02*10^23 approx.
So n=N/Na (n=mole number, N=number of atoms, Na=Avogadro number)
n=1.0*10^15/6.02*10^23
n=1.6 * 10^-9
So 1.0*10^15 atoms of Sodium represent 1.6*10^-9 mol.
Hope this Helps! :)