Answer:
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Answer:
False
Explanation:
The slope of a velocity-time graph gives acceleration. Acceleration can be defined as the change in velocity with time.
A slope denotes the gradient of line. It takes into consideration the changes on both y and x axis. The ratio of the changes gives the slope.
On a velocity-time graph, the y-axis is the velocity and the x-axis is time. The change in velocity with time gives acceleration.
The slope of an acceleration
-time graph is not velocity.
a) The reaction is exothermic since the overall enthalpy change is negative. this means that the system has lost energy to the environment, namely, the apparatus and due to drought.
b) We first calculate the number of moles in 3.55 grams of magnesium.
number of moles= mass/ atomic mass
=3.55/24
=0.1479 moles(to 4sf)
now, if 2 moles of magnesium give -1204kJ
How much energy is given by 0.1479 moles
= (0.1479×-1204kJ)
=-89.0358kJ (don't forget the negative sign)
c) two molesof MgO produces -1204kJ of energy
then -234kJ will be produced by
=(-234kJ×2moles)/1204kJ
=0.3887moles
one mole of MgO weighs 24+16=40
therefore the mass produced is 0.3887moles×40=15.548grams
(d) we first find the number of moles of MgO in 40.3 grams
number of moles=mass/RFM
=40.3g/40= 1.0075moles
if 2 moles of MgO give 1204 kJ then decomposing 1.0075 moles requires
(1.0075 moles×1204kJ)/2=606.515kJ
If the solution is BASIC than it will turn purple but if ACIDIC it will turn pink.
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>
