Answer:
25.2 kJ
Explanation:
The complete question is presented in the attached image to this answer.
Note that, the heat gained by the 2.00 L of water to raise its temperature from the initial value to its final value comes entirely from the combustion of the benzoic acid since there are no heat losses to the containing vessel or to the environment.
So, to obtained the heat released from the combustion of benzoic acid, we just calculate the heat required to raise the temperature of the water.
Q = mCΔT
To calculate the mass of water,
Density = (mass)/(volume)
Mass = Density × volume
Density = 1 g/mL
Volume = 2.00 L = 2000 mL
Mass = 1 × 2000 = 2000 g
C = specific heat capacity of water = 4.2 J/g.°C
ΔT = (final temperature) - (Initial temperature)
From the graph,
Final temperature of water = 25°C
Initial temperature of water = 22°C
ΔT = 25 - 22 = 3°C
Q = (2000×4.2×3) = 25,200 J = 25.2 kJ
Hope this Helps!!!
The total mass is 10.57+6.96=17.53 g.
So, the percent by mass of magnesium is (10.57)/(17.53) * 100 = <u>60.3%</u>
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The percent by mass of oxygen is (6.96)/(17.53) * 100 = <u>39.7%</u>
Answer:(I didn’t really know where to Wrigh-)
Explanation: Gas bubbles appear after a chemical reaction has occurred and the mixture becomes saturated with gas. The chemical change that creates the gas is completed after the gas bubbles leave the mixture.
<u>Given:</u>
Enthalpy change (ΔH) for SO3 decomposition = +790 kJ
Moles of SO3 = 2.1 moles
<u>To determine:</u>
Energy required when 2.1 moles of SO3 reacts
<u>Explanation:</u>
The decomposition reaction is -
2SO3(g) → 2S(s) + 3O2 (g)
Energy required when 2 moles of SO3 reacts is 790 kJ
Thus, for 2.1 moles of SO3 the energy requirement would be
= 2.1 moles SO3 * 790 kJ/2 moles SO3 = 829.5 kJ
Ans: 830 kJ are required when 2.1 moles of SO3 reacts.