Answer:
hco3
Explanation: bc i said so
Answer:
-6.4x10⁻¹⁹ C
Explanation:
The elementary charge of one electron is -1.60x10⁻¹⁹C, so each electron has its charge, and a sample with more than one electrons will have a multiple of its charge, which is proportional to the number of electrons. So, if the oil droplet had 4 electrons, thus the charge will be four times the elementary charge:
4*(-1.60x10⁻¹⁹) C = -6.4x10⁻¹⁹ C
Answer:
24.03 J/mol.ºC
Explanation:
For a calorimeter, the heat lost must be equal to the heat gained from water plus the heat gained from calorimeter, which has the same initial temperature as the water.
-Qal = Qw + Qc (minus signal represents that the heat is lost)
-mal*Cal*ΔTal = mw*Cw*ΔTw + Cc*ΔTc
Where m is the mass, C is the specific heat, ΔT is the temperature variation, al is from aluminum. w from water and c from the calorimeter. Cw = 4.186 J/gºC
-25.5*Cal*(22.7 - 100) = 99.0*4.186*(22.7 - 18.6) + 14.2*(22.7 - 18.6)
1971.15Cal = 1699.10 + 58.22
1971.15Cal = 1757.32
Cal = 0.89 J/g.ºC
The molar mass of Al is 27 g/mol
Cal = 0.89 J/g.ºC * 27 g/mol
Cal = 24.03 J/mol.ºC
The heat is involved in the production of 5.0 mol of MgO is 180 Kj
calculation
2 Mg (s) +O2 → 2 MgO
From the equation above two moles of MgO is used therefore
72.3 is for 2 moles
that is 72.3 kj = 2moles
? = 5 moles
by cross multiplication
= 72.3 kj × 5/2 = 180 Kj
