Answer:
Molar mass of MgCO3 = 84.3 g/mol
Explanation:
What is the molar mass of magnesium carbonate.
Molar mass of a substance is defined as the mass of one mole of the substance expressed in grams hence its unit is gram per mole (g/mol)
MgCO3 is a compound and it's molar mass would be the sum of the molar masses of the elements that make up the compound. MgCO3 contains 1 atom of magnesium, one atom of carbon and 3 atoms of oxygen
Molar mass of Magnesium = 24.3g
Molar mass of Carbon =12g
Molar mass of Oxygen = 16g
Molar mass of MgCO3 will be
24.3 + 12 + 16×3
= 24.3 + 12 +48 = 84.3 g/mol
Molar mass of MgCO3 = 84.3 g/mol
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
I think that it would be 12
HCCH? That would be drawn like shown below. It doesn't look the greatest, sorry about that.
