Answer:12.5
Explanation: Divide 50$ by the 4 hours and you will get 12.5 which is $12.50.
The answer is hydrogen. the first element in the periodic table.
Answer:
The enthalphy change of the given reaction is -280 KJ.
Explanation:
X 2 + 3 Y 2 ⟶ 2 XY 3 Δ H 1 = − 380 kJ ....Eq-1
X 2 + 2 Z 2 ⟶ 2 XZ 2 Δ H 2 = − 130 kJ ....Eq-2
2 Y 2 + Z 2 ⟶ 2 Y 2 Z Δ H 3 = − 260 kJ ....Eq-3
4 XY 3 + 7 Z 2 ⟶ 6 Y 2 Z + 4 XZ 2 ΔH ....Eq-4
<em>By Hess law,</em>
<em> The heat of any reaction ΔH for a specific reaction is equal to the sum of the heats of reaction for any set of reactions which in sum are equivalent to the overall reaction:</em>
Eq-4 can be manipulated as,
Eq-4 = -2(Eq-1) +2(Eq-2) +3(Eq-3)
By Hess law, same happen with their enthalphy
Therefore,
ΔH = -2(ΔH1) + 2(ΔH2) + 3(ΔH3)
= -2 × -380 + 2 × -130 + 3 × -260
= -280 KJ
Answer: B. 29.76°C
Explanation:
The melting point is known as an intensive property of matter. This means the melting point is not affected by the amount of mass. Whether the metal is really large or small, the melting point of gallium (Ga) is roughly 29.76 degrees Celsius.
