Answer:
Increasing the temperature will cause chemical changes to occur faster. Decreasing the temperature, causes the particles to lose energy which causes them to move around less and slower. The less they move, the less collisions occur, and the less reactions occur between the chemicals = slower reaction rate.
Explanation:
Answer:
2-4 minutes
Explanation:
Fastest changing temperature means larger change in temperature when subtracting final temperature from initial temperature in a given time period (given time period is 2 minutes for all the options)
For 0-2 minutes, our final temperature was 40 (at 2 min) and initial temperature was 20 (at 0 min), thus temperature change was only 20 C.
For 2-4, our final temperature was 80 (at 4 min) and initial temperature was 40 (at 2 min) thus temperature change was 40 C.
For 4-6, our final temperature was 100 (at 6 min) and initial temperature was 80 (at 4 min) thus temperature change was 20 C.
We are not given temperature at 8 min so option D is invalid.
As we can clearly see that in a given 2 minute period, option B has the fastest change because it changed 40C when compared to other options that changed only 20C from starting temperature.
Hope that makes sense.
Answer:
Explanation:
2NO3, Ca2+
Spectator ions exists in both sides of the equation. These ions are present in both sides thus cancel out (they do not contribute to reaction...i.e. they only watch or spectate ;) )
Enthalpy change during the dissolution process = m c ΔT,
here, m = total mass = 475 + 125 = 600 g
c = <span>specific heat of water = 4.18 J/g °C
</span>ΔT = 7.8 - 24 = -16.2 oc (negative sign indicates that temp. has decreases)
<span>
Therefore, </span>Enthalpy change during the dissolution = 600 x 4.18 X (-16.2)
= -40630 kJ
(Negative sign indicates that process is endothermic in nature i.e. heat is taken by the system)
Thus, <span>enthalpy of dissolving of the ammonium nitrate is -40630 J/g</span>
