Answer: 250 kJ
Explanation: According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to Hess’s law, the chemical equation can be treated as algebraic expressions and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
(1)
(2)
Net chemical equation:
(3)
Adding 1 and 2 we get,
(4)
Now dividing equation (4) by 4, we get
(4)
Answer:
A. The energy of moving particles near a fire
Explanation:
Answer:
18 grams
Explanation:
Because 17,190 yrs divided by the amount of years it takes for a half-life to occur is 3. So 3 half life’s happen, so you divide 144/2 once, equaling 72. You divide 72/2 again (another half-life) and you get 36. You then calculate the third half life by dividing 36/2 which equals 18 grams.
the first law says that the change in internal energy of a system is given by:
δ<span>E = δq + δw</span>
where δ<span>E is the i change in internal energy, </span>
<span>δq is the amount of thermal energy added to the system from the surroundings </span>
<span>δw is the l work done *on* the system *by* the surroundings. </span>
<span>For a system only undergoing expansion work,
δw = -p</span>δ<span>V, so: </span>
δE = δq - p δ<span>V </span>
when δV = 0, then δe=δq
The balanced equation would be 2NaOH + H2SO4 → Na2SO4 + 2H2O
