Answer:
35 amu
Explanation:
In an atom, only masses of protons and neutrons are relevant. electrons are so small in size that their masses are negligible.
The mass of 1 proton/neutron is 1amu.
A) 4400 kj of heat released into surroundings
<h3>Further explanation</h3>
Reaction
C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O, the ∆H is –2200 kJ
Reaction exothermic( ∆H=-, released heat to surrounding) and for combustion of 1 mole of C3H8
So for two moles of C3H8, the enthalpy :
Answer:
D
Explanation:
Solar panels are not toxic, so option A goes out the window.
Aesthetics don't really matter, so option B follows it out.
Option C makes a little sense, but less so than Option D. They aren't nearly as heavy as some of our current energy production methods.
Solar panels are expensive, hard to store properly, and most are between 15 and 20 percent efficiency, compared with a diesel motor's 40 percent.
Answer:
<u>225.6 kJ</u>, <em>assuming the water is already at 100 °C</em>
Explanation:
The correct answer to this question will depend on the initial temperature of the water to which heat is added to produce steam. Energy is required to raise the water temperature to 100°C. At that point, an energy of vaporization is needed to convert liquid water at 100 °C to water vapor at 100°C. The heat of vaporization for water is 2256.4 kJ/kg. The energy required to bring 100g of water from a lower temperature to 100°C is calculated at 4.186 J/g°C. We don't know the starting temperature, so this step cannot be calculated.
<em><u>Assuming</u></em> that we are already at 100 °C, we can calculate the heat required for vaporization:
(100.0g)(1000.0g/1 kg)(2256.4 kJ/kg) = 225.6 kJ for 100 grams water.
