Answer:
Each molecule of O2 is made up of 2 oxygen atoms. So 1 mole of O2 molecules is made up of 2 moles of oxygen atoms. Therefore 1 mole of oxygen gas contains 2 moles of oxygen atoms. And 0.4 moles of oxygen gas contains 0.8 moles of oxygen atoms.
First you need to find the mass of one mole of the element. (say Fe)
Find Fe on the periodic table, it should tell you what the average atomic mass is.
The average atomic mass = mass of one mole.(in this case it is 55.85g)
Take your moles (1.35mol Fe) and multiply it by the mass of one mole (55.85g)
1.35mol*55.85g/mol=75.39g
(Just repeat that method for the other problems) use the formula <span><span>moles=<span><span>mass</span><span>Molar mass
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a light bulb is the example of chemical energy
Answer:
- 50.7 kJ.
Explanation:
- To get the enthalpy change for the reaction:
Mn₃O₄(s) + CO(g) ⟶ 3MnO(s) + CO₂(g).
- We must orient the given reactions in a way that its sum give the required reaction.
The first reaction be as it is:
Mn₃O₄(s) + 4CO(g) ⟶ 3Mn(s) + 4CO₂(g), <em>ΔH₁ = 255.6 kJ.</em>
The second reaction should be reversed and multiplied by 3 and also the value of its ΔH must multiplied by (- 3):
3Mn(s) + 3CO₂(g) ⟶ 3MnO(s) + 3CO(g), <em>ΔH₂ = (- 3)(102.1 kJ) = - 306.3 kJ.</em>
- By summing the two reactions after the modification, we get the required reaction:
<em>Mn₃O₄(s) + CO(g) ⟶ 3MnO(s) + CO₂(g).</em>
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<em>∴ ΔH rxn = ΔH₁ + ΔH₂ = (255.6 kJ) + (- 306.3 kJ) = - 50.7 kJ.</em>
Answer:
1.Less Predators
2. More likely to survive.....
