Note that
The heating value of standard coal is about 30,080 kJ/kg
1 L of water has a mass of 1.0 kg
The mass of 15 L of water = 15 kg.
The latent heat of vaporization of water is about 2260 kJ/kg,
The energy required to boil 15 L of water is
(2260 kJ/kg)*(15 kg) = 33900 kJ
The mass of coal required to provide this energy is
(33900 kJ)/(30080 kJ/kg) = 1.127 kg
Because 1 kg = 2.205 lb, the mass of coal required is
(1.127 kg)*(2.205 lb/kg) = 2.485 lb
Answer: 2.49 lb (nearest hundredth)
Answer:
6 J
Explanation: Work done(J) = Force(N) × Distance(m) along the direction of force.
Given, Force=2 N, Distance=3 meters
∴ Wok done (J) = 2 × 3 = 6 J.
To answer this question, all you to do is to divide the mass by the molar mass and that should get you your moles.

<em>= 3.5 mol NH₄</em>
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Over here you have to use the formula: <span>P1/T1= P2/T2
P1= 7.58
T1= 639
P2= ?
T2= 311
</span><span>7.58/639 = ?/311
</span>= 3.689 kPa
Evaporite. Gypsum (Mineral) and Halite (Rock Salt) are examples of evaporites. Usually Gypsum forms first and then Halite.