Answer:
177.8kJ/mol
Explanation:
In this reaction, the heat of decomposition is the same as the heat of formation. This is a decomposition reaction.
Given parameters:
ΔHf CaCO₃ = -1206.9kJ/mol
ΔHf CaO = −635.6 kJ/mol
ΔHf CO₂ = −393.5 kJ/mol
The heat of decomposition =
Sum of ΔHf of products - Sum of ΔHf of reactants
The equation of the reaction is shown below:
CaCO₃ → CaO + CO₂
The heat of decomposition = [ -635.6 + (-393.5)] - [−1206.9 ]
= -1029.1 + 1206.9
= 177.8kJ/mol
We know the formula of the density:
ρ =
;
So the mass will be equal to:
m = ρ * V = 2.70 * 21.3 = 57,51 g =
57510 mg of substance.
So the answer is 57510.
Answer:
NH3 is polar due to the bonds between nitrogen and hydrogen which have different electronegativity and due also to its asymmetrical shape.
Explanation:
NH3 is polar as there are 3 dipoles in the ammonia molecule that do not balance each other out.
Considering the N-H bond which is polar because N with an electronegativy of 3.0, is more electronegative than H, with an electronegativity of 2.1. The is overall asymmetrical shape of NH3
means that the dipoles remains unbalanced and do cancel out each other making the NH3 polar.
When looking down the groups the elements have an equal number of electrons in the outer shell. This means they react in a similar way making it easier for scientists to use.
Answer is: 0,0095 mol of hydrogen gas will be produced in reaction.
Chemical reaction: Ca + 2HCl → CaCl₂ + H₂.
m(Ca) = 0,38 g.
n(H₂) = ?
n(Ca) = m(Ca) ÷ M(Ca).
n(Ca) = 0,38 g ÷ 40 g/mol
n(Ca) = 0,0095 mol.
from reaction: n(Ca) : n(H₂) = 1 : 1.
n(H₂) = n(Ca) = 0,0095 mol.
n - amount of substance.
