Chemistry Study Material: Enthalpy, Dilution, Equilibrium Constant, Spectrometry Experiment

MATH
Question 2:
The rate order for the first order chemical reaction is given by:c=c0 e−kt , where c is the
concentration at time t, c0is the concentration at time t=0
a) Equation for ln(c)
ln ( c )=ln (c0 e−kt )¿ ln ( c0 ) +ln ( e−kt )¿ ln ( c0 ) −kt
b) The equation ln ( c )=−kt+ ln ( c0 ), is in the form of y=mx+c with slope of −kt and y-
intercept is ln ( c0 ),
Question 3:
Mass required to make 250 cm3, of 0.100 M MgCl2 solution: Molar mass of MgCl2 =95.2
Molarity= moles
Volume 0.100= n
0.25n=0.1 ×0.25=0.025 moles of MgC l2
Mass=Molar mass × number of moles¿ 95.2 ×0.025¿ 2.38 g
Question 4
Diluting 25cm3 of 5.00 NaOH with 125 cm3of water. The final volume will be 25+125 =150cm3.
c2 V 2=c1 V 1sc2= c1 V 1
V 2
= 5.00 ×25
150 ¿ 0.8333 M NaOH
Question 5
The variation of the equilibrium constant, K with temperature, T for an enzyme reactor

a) Completing the table
T/K 289.0 294.2 298.0 304.9 310.5
K/107 7.25 5.25 4.17 2.66 2.00
103/(T/K) 3.4602 3.3990 3.3557 3.2798 3.2206
ln (K) 18.099
1
17.7763 17.5460 17.0964 16.8112
b) The figure below shows the graph of ln (k) verses 1/T, with the line of best fit
c) The slope is
∆ ( ln ( K ) )
∆ ( 1
T ) =5445