Henry Moseley developed the concept of atomic numbers.
The enthalpy of formation has a negative sign, which means that the reaction is exothermic. In other words, when ethanol is formed, heat is released to the surroundings as a by-product. The reaction for the formation of ethanol is written below:
<em>C₂H₄ + H₂O → C₂H₅OH</em>
Answer:
Mass of He required = 8.0 g
Explanation:
Given,
Initial moles of He = 2.0 mol
Initial pressure = 1.00 atm
final pressure = 2.00 atm
Ideal gas equation,
PV = nRT
As V, R and T are constant
So, 
Molar mass of He = 4.00 g/mol
No. of moles of He needs to be added = 4.0 - 2.0 = 2.0 mol
Mass = No. of mole × Molar mass
= 2.0 × 4.0
= 8.0 g
In stones:
1 kg ------------ 0.157473 stones
60 kg ---------- ??
60 x 0.157473 / 1 => 9.44838 stones
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in pounds:
1 kg ----------------- 2.20462 pounds
60 kg --------------- ??
60 x 2.20462 / 1 => 132.277 pounds
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hope this helps!
