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
Answer: 4P + 3O2 → P4O6
Explanation: plz give brainliest
It gets hotter because if the heat waves from the sun we all know the sun is really hot obviously so the heat wave make it hot
Answer:
Density of the oil is lesser than that of the water
Explanation:
The density of water is given as 1.0g/cm³.
Salad oil is found to float on water, this implies that the density of this salad oil is lesser than that of the water.
- When the density of a substance is greater than another, it will sink. If the density of the salad oil is greater than that of water, then it will sink and not float.
- Since the oil floats on water, the density of the oil is lesser than that of the water.
Density is the mass per unit volume of a substance.
Mass % of NaCl = 0.9 % (m/v)
Density of 0.9 % NaCl is about 1.0 g/mL
Volume of NaCl in mL :
= 11.25 mL NaCl
