Answer:
The answer is: (a) positive; (b) negative.
Explanation:
The change in enthalpy (ΔH) of a reaction is the amount of energy absorbed or released during a chemical reaction carried out at constant pressure.
a) In an endothermic chemical reaction, heat energy is absorbed by the system from the surrounding. Therefore, the sign of enthalpy change for an endothermic process is positive, ΔH= positive.
b) In an exothermic chemical reaction, heat energy is released by the system into the surrounding. Therefore, the sign of enthalpy change for an exothermic process is negative, ΔH= negative.
Answer:
His kinetic energy is converted into potential energy.
Explanation:
The balanced chemical reaction is:
<span>3N2H4(l)→4NH3(g)+N2(g)
</span>
The amounts given for the N2H4 reactant will be the starting point for our calculations.
2.6mol N2H4 ( 4 mol NH3 / 3 mol N2H4 ) = 3.47 mol NH3
4.05mol N2H4 ( 4 mol NH3 / 3 mol N2H4 ) = 5.4 mol NH3
63.8g N2H4 <span>( 4 mol NH3 / 3 mol N2H4 ) = 85.07 mol NH3</span>
It is A) 1,482 cm3 ..............
<span>The ideal gas law.
PV=nRT
pressure x volume = moles x Faraday's constant x Temp Kelvin (C+273)
Original data
Pressure 1 atmosphere
Volume 1 liter
Temp 25C = 298K
New data
Volume 0.5 liter
pressure X
Temp 260C = 533K
P1v1T1 = P2v2T2
plug and chug.
(1)(1)(293) = (x)(0.5)(533)
Solve for X, which is the new pressure. </span>
