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:
THE SPECIFIC HEAT OF THE METAL IS 0.8983 J/g °C
Explanation:
In solving the problem, we have to understand that:
Heat lost by the metal = Heat gained by the water in the bomb calorimeter
First is to calculate the heat evolved from the reaction
Heat = mass * specific heat * change in temperature
Mass of water = 50 g
specific heat of water = 4.184 J/g °C
Change in temperature = 23 - 21 = 2 °C
So therefore,
Heat = 50 * 4.184 * 2
Heat = 418.4 J
Next is to solve for the specific heat of the metal;
Heat lost by the metal is the same as the heat gained by water
Heat = mass * specific heat of metal * change in temperature
Change in temperature = 39.4 °C - 23 °C = 16.4 °C
418.4 = 28.4 * C * 16.4
C = 418.4 / 28.4 * 16.4
C = 418.4 / 465.76
C = 0.8983 J/ g °C
The specific heat of the metal is hence 0.8983 J/g °C
The patient should be given 285.71 ml.
1000 ml contains 70 gr glucose.
x contains 20 gr glucose.
x=1000*20/70
Answer:
23.59
Explanation:
molarity=moles x1000÷volume
When the molar mass M = mass (g)/ no.of moles (Mol)
∴ moles= 0.271 g / M
By using the gas equation:
PV = n RT
when P is the pressure = 847 mmHg / 760 = 1.11 atm
V is the volume = 0.294 L
n = 0.271 / M
R is constant = 0.0821
T= 140+273 = 413 K
so by substitution:
when n = PV/RT
∴ 0.271/ M = 1.11 atm *0.294 L/ 0.0821 *413
∴ M = 28
when the empirical formula of CH2 = 12+2 = 14
∴ the exact no.of moles = 28/14 = 2
∴the molecular formula = 2(CH2) = C2H4
