Hey there!
There are 6.022 x 10²³ particles in 1 mole.
We have 3.55 moles.
6.022 x 10²³ x 3.55
2.14 x 10²⁴
This is how many particles we have.
NaCl has 2 atoms for every unit.
So we multiply this by 2.
2 x 2.14 x 10²⁴ = 4.28 x 10²⁴
There are 4.28 x 10²⁴ atoms in 3.55 moles of sodium chloride.
Hope this helps!
CH4+2O2=> 2H2O+CO2
C- 1 on both sides
H- 4 on both sides
O - 4 on both sides
Their are 18 covalent bonds in a molecule of cyclohexane
According to this formula:
Q = M*C*ΔT
when we have M ( the mass of water) = 200 g
and C ( specific heat capacity ) of water = 4.18 J/gC
ΔT (the difference in temperature) = Tf - Ti
= 100 - 24
= 76°C
So by substitution:
Q = 200 g * 4.18 J/gC * 76 °C
= 63536 J
∴ the amount of heat which be added and absorbed to raise the temp from 24°C to 100°C is = 63536 J
I know for number 4 the answer is c, sorry I can't help with the others.