Answer:
342.8 kJ are absorbed
Explanation:
In the reaction:
4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(l) ΔH° = 1168 kJ
<em>As ΔH > 0, the heat is absorbed. Also, when 4 moles of NH3 are involved in the reaction, there are absorbed 1168 kJ</em>.
Having this in mind, moles of NH3 in 20.00g are:
20.00g × (1mol / 17.0307g) = <em>1.174 moles</em>
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Thus, 1.174 moles of NH3 absorbed:
1.174 moles × (1168 kJ / 4 moles) = <em>342.8 kJ are absorbed</em>.
Answer:
20.67 kcal of energy is released.
Explanation:
It is given that, an exothermic reaction releases 86.5 kJ. We need to convet kJ to calories.
Since,
1 kcal = 4.184 kJ
So,
1 kJ = 0.239 kcal
For 86.5 kJ,
86.5 kJ = (0.239 × 86.5) kcal
86.5 kJ = 20.67 kcal
So, 20.67 kcal of energy is released.
Answer:
132.17 g
Explanation:
The reaction given , in the question is -
CH₄ (g ) + 4 S ( g ) ---> CS₂ ( g ) + 2H₂S ( g )
From the reaction , 4 mole of S is required for the production of 1 mole of CS₂ .
since ,
Moles of CS₂ = given mass of CS₂ / Molecular weight of CS₂
Since ,
the Molecular weight of CS₂ = 76
Given , mass of CS₂ = 72.57 g
Moles of CS₂ = 72.57 / 76 = 0.95 mol
Since ,
The yield is 92.0 % .
Moles of S required = 4 * 0.95 mol / 0.92 = 4.13 moles
Mass of S required = 4.13 * 32 = 132.17 g .
Answer:
Magnesium is the most reactive element. it is higher than the other elements (Fe, Pb, Zn) in the electrochemical series
