Answer:
41.3kJ of heat is absorbed
Explanation:
Based in the reaction:
Fe₃O₄(s) + 4H₂(g) → 3Fe(s) + 4H₂O(g) ΔH = 151kJ
<em>1 mole of Fe3O4 reacts with 4 moles of H₂, 151kJ are absorbed.</em>
63.4g of Fe₃O₄ (Molar mass: 231.533g/mol) are:
63.4g Fe₃O₄ × (1mol / 231.533g) = <em>0.274moles of Fe₃O₄</em>
These are the moles of Fe₃O₄ that react. As 1 mole of Fe₃O₄ in reaction absorb 151kJ, 0.274moles absorb:
0.274moles of Fe₃O₄ × (151kJ / 1 mole Fe₃O₄) =
<h3>41.3kJ of heat is absorbed</h3>
<em />
Answer:
5.7 moles of O2
Explanation:
We'll begin by writing the balanced decomposition equation for the reaction. This is illustrated below:
2KClO3 —> 2KCl + 3O2
From the balanced equation above,
2 moles of KClO3 decomposed to produce 3 moles of O2.
Next, we shall determine the number of mole of O2 produced by the reaction of 3.8 moles of KClO3.
Since 100% yield of O2 is obtained, it means that both the actual yield and theoretical yield of O2 are the same. Thus, we can obtain the number of mole of O2 produced as follow:
From the balanced equation above,
2 moles of KClO3 decomposed to produce 3 moles of O2.
Therefore, 3.8 moles of KClO3 will decompose to produce = (3.8 × 3)/2 = 5.7 moles of O2.
Thus, 5.7 moles of O2 were obtained from the reaction.
<h2>Long term benefits</h2>
- Increased heart rate.
- Increased breathing rate.
- Increase in systolic blood pressure.
- Increase vasodilation of blood vessels in the working muscles.
- Increased volume of air in the lungs.
- Increased stroke volume.
- Increased cardiac output.
Answer:
Wide melting point range - impure sample with multiple compounds
Experimental melting point is close to literature value - pure sample of a single compound
Experimental melting point is below literature value - impure sample with multiple compounds
Narrow melting point range - pure sample of a single compound
Explanation:
The melting point of substances are easily obtainable from literature such as the CRC Handbook of Physics and Chemistry.
A single pure substance is always observed to melt within a narrow temperature range. This melting temperature is always very close to the melting point recorded in literature for the pure compound.
However, an impure sample with multiple compounds will melt over a wide temperature range. We also have to recall that impurities lower the melting point of a pure substance. Hence, the experimental melting point of an impure sample with multiple compounds is always below the literature value.
