Answer:
The (H30+) is 4,13x10-8
Explanation:
We use the formula
Kwater = (H30 +) x (OH-)
1.00e-14 = (H30 +) x 2.42e-7
(H30 +) = 1.00e-14 / 2.42e-7 = 4.13e-8M
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
The <span>form of energy of each substance contains.</span>
firewood, Kinetic energy
beans, Potential energy
flames, Kinetic energy
hiking, Kinetic energy
moving water, Kinetic energy
For this item, we find first the mass of the compound with the empirical formula. That is,
molar mass = 12 (for C) + 1 (for H)
= 13 g/mole
Then, we divide the given mass of the molecular formula by the mass of the empirical formula.
n = 52.07 / 13 = 4
Therefore, the molecular formula is C₄H₄.
