Answer:
Enthalpy change = 74.36 kJ
Explanation:
Enthalpy change is defines as the heat absorbed or evolved during a chemical reaction at constant pressure and volume
Reaction:
H2O(l) --> H2O(g)
DHr = mCsDT
Where m is the mass of water
Cs is the specific heat capacity
DT is the temperature difference
= 31.6 * 4.18 * (25 - 3.2)
= 2879.518 J
DHvap = 44kJ/mol
Moles of water = mass/molecular weight
Molecular weight = (1*2) + 16
= 18g/mol
Moles of water = 31.6/18
= 1.756 moles
DHvap = 44 * 1.756
= 77.244kJ
DH = DHproduct - DHreactant
DHproduct = DHvap = 77.24kJ
DHreactant = DHr = 2879.518J = 2.880kJ
= 77.24 - 2.880
DH = 74.36kJ
Enthalpy change = 74.36 kJ
Difference Between Empirical and Molecular Formulas. The key difference between empirical and molecular formulas is that an empirical formula only gives the simplest ratio of atoms whereas a molecular formula gives the exact number of each atom in a molecule. In chemistry, we often use symbols to identify elements and molecules.
Hope I helped :)
Answer:
- 0.1852
- 0.0947
- 0.7201
- 3.0345 kg CO
/ Kg C
H
- 15.3848 Kg air / kg C H
Explanation:
Molar masses of each product are :
Butane = 58 kg /kmol
Oxygen = 32 kg/kmol
Nitrogen = 28 kg/kmol
water = 18 kg/kmol
<u><em>1) Calculate the mass fraction of carbon dioxide </em></u>
= ( 4 * 44 ) / ( (5 * 18) + (4 *44 )+ (24.44 * 28) )
= 176 / 950.32
= 0.1852
<em><u>2) Calculate the mass fraction of water </u></em>
= ( 5 * 18 ) / (( 5* 18 ) + ( 4*44) + ( 24.44 * 28 ))
= 90 / 950.32
= 0.0947
<em><u>3) Calculate the mass fraction of Nitrogen </u></em>
= (24.44 * 28 ) / ((4 * 44 ) + ( 24.44 * 28 ) + ( 5 * 18 ))
= 684.32 / 950.32
= 0.7201
<em><u>4) Calculate the mass of Carbon dioxide in the products</u></em>
Mco2 = ( 4 * 44 ) / 58 = 3.0345 kg CO / Kg C H
<u>5) Mass of Air required per unit of fuel mass burned </u>
Mair = ( 6.5 * 32 + 24.44 *28 ) / 58 = 15.3848 Kg air / kg C H
<h3>Water</h3>
<em>Specific heat is defined as the amount of heat one gram of a substance must absorb or lose to change its temperature by one degree Celsius.</em>
- For water, this amount is one calorie, or 4.184 Joules.
Answer:
Gravitational force is also decreases.
Explanation:
Gravitational force is directly proportional to the mass of an object and inversely properly to the distance between their centres. Directly means if one increases the other automatically increases or if one decreases, the other also decreases. There is a direct relationship between mass and gravitational force so if mass of the bodies decrease, the gravitational force is also decreases.
