Answer:
-105 kJ
Explanation:
The enthalpy change of a reaction is the sum of the energy of the bonds of the reactants and the products. The bonds at the reactants are being broken, so it's an endothermic reaction, so the bond energy must be positive.
The bonds at the products are being formed, so the process is exothermic, and the bond energy must be negative. There are being broken 1 N≡N bond and 3 H-H bonds, and are being formed 6 N-H bonds:
Reactants: 945 + 3*432 = 2241 kJ
Products: 6*(-391) = -2346 kJ
ΔH = 2241 - 2346
ΔH = -105 kJ
Answer:
If you want the first option you need 2.5M.
If you want the second, you will end up with 120ml so your starting solution is:
0.5x (120/20) = 3.0M
This assumes that there’s no loss of volume on mixing. To remove that uncertainty, start with the 20ml of acid and add water, mixing, till you get the right volume.
Answer:
3000J
Explanation:
Formula: Work = Force × Distance
Solution: Work = 200N × 15m
Answer = 3000N/m or 3000J
Δt = i Kf m
2.86 °C = (1) (1.86 °C kg mol-1) (x / 0.750 kg)
2.86 °C = (2.48 °C mol-1) (x)
x = 1.1532 mol
33.7 g / 1.1532 mol = 29.2 g/mol
Answer:
An ionic bond is formed between the two atoms
Note: The missing figure in the question is found in the attachment below
Explanation:
Ionic bonding is a type of bonding which involves the transfer of electrons from from atom to another resulting in the formation of positive and negative ions.
The two atoms in A are a magnesium atom and and an oxygen atom.
The magnesium atom possesses two valence shell electrons which are transferred to the oxygen atom which has six valence shell electrons.
The transfer of two electrons from magnesium atom to oxygen atom makes it to become a positive ion with a charge of +2.
The oxygen atom receiving two extra electrons turns it to a negative ion with a charge of -2.
Electrostatic forces of attraction then attracts the two oppositely charged ions to each other, thereby forming an ionic bond between them.