depth = side/lenght
the cube has all congruent sides
Volume = l³
Volume = 10³
Volume = 1000 cm³
Hey there, The answer is A. Free electrons.
Answer:
SO42 - Trigonal planar ion
Explanation:
The SO4^2- ion is tetrahedral and not trigonal planar because the sulphur atom has four regions of electron density which includes the lone pair of electrons on sulphur atom.
This accounts for the observed tetrahedral arrangement of electron pairs around the central sulphur atom in SO4^2- ion, hence the answer.
Answer:
Explanation:
A foam coffe cup is considered a perfectly insulated system: heat energy is not exchanged with the surroundings.
Under that assumption, the heat released by the chemical reaction is equal to the heat absorbed by the system.
1. Heat absorbed by the system:
Use the equation Heat = Q = m × C × ΔT, with:
- m = 126 g (the amount of solution produced)
- C = specific heat of pure water = 4.186 J/gºC
- ΔT = increase of temperature = 24.70 ºC - 21.00ºC = 3.70ºC
Q = 126g × 4.186J/gºC × 3.70ºC = 1,951.5J
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<em><u>2. Enthalpy of the reaction</u></em>
The enthalpy must be reported in kJ/mol.
Then, convert juoles to kilojoules, dividing by 1,000; and divide by 2.00 moles, which is the amount of compound that reacted:
- ΔHrxn = 1,951.5J × (1kJ / 1,000J) × (1 / 2mol) ≈ 0.9758 kJ/mol
Round to <em>3 significant figures</em>: 0.976 kJ/mol
