Distinguish between the followd)i+tx)*up1 i k sv-x-h46vrrk n*rvf ing terms:

1.Precision and accuracy.
2.Systematic error and random error.

  Which of the following:g4cu5lt81i3t8r ujqnn;tgq is correct?

  A thermometer was used to reco -rl8 (9)slbd8uik anfrd the temperature of pure boiling water at sea level three times and the values(rilk -d8l 9 un8)abfs were : $85.6^{\circ}C$,$85.7^{\circ}C$,$85.5^{\circ}C$.What can be said about the accuracy and precision of these values?

  Which statement best describes the relationship between x and y on the graph bez9t20s rx8sg.lre x5vlowzl2r 08sev5xts grx.9 ?

  For a first order reaction, the relationo;+mi 28 r 1c*kykywqc suf3dmnp 924kship between rate and the concentration of a reactant, [A],8cy2k32ryc;inmmq 41d sf+okuw*9 kp can be shown using the following equation: rate =k[A].
The data below gives the rate information for the first order reaction that proceeds in the thermal decomposition of reactant A.



1.On the axes above, draw a graph based on the provided data.
2.The effect of time on the concentration of reactant B for a zero-order reaction was plotted on the graph below.


(i)Draw a line of best fit on the graph above.
2.2.Describe the relationship between time and concentration.
Concentration  ----待选择----decreasesincreases  linearly with time

  The relationship between pressure and temperature of a known volume an i0r+r ocdo)z1zbd0 t6 h961hjhk*nprd amount of gas can be described using Gay-Lussac’s law which states that pressure is directlyr0ohor0h) tdc6r bhzj91 k i*+dp61zn proportional to temperature.
P∝T
Where P is pressure in Pa, and T is temperature in K.


1.On the axes above, sketch the graph of P∝T.

2.State two features that would need to be added to your sketched graph to turn it into a drawn graph.

3.The proportionality can be shown in an equation by incorporating a constant, k. The equation becomes P=kT, and follows the format of the equation of a straight line.

3.1.State the feature of a straight line that k represents in this context.
3.2.Deduce the y-intercept of the straight line.straight line=  (Pa)

  Solid sodium carbonate reacts with excess nitricy+ r*(n :xgykc acid of 0.10 mol dm$^{-3}$ as shown in the equation below:
$Na_2CO_3$(s) + 2$HNO_3$(aq)→$H_2O$(l) + $CO_2$(g) + 2$NaNO_3$(aq)
1.State a method to measure the rate of reaction other than measuring the volume of gas collected.
2.1.Sketch a graph to show the volume of gas produced over time.
2.2.Explain the shape of your graph using the collision theory.
$CO_2$ is produced in the reaction; hence, the volume of $CO_2$  ----待选择----increasesdecreases  over time.
3.On the same graph as in part(bi), sketch another line to show the volume of gas collected over time at a concentration of 0.05 mol dm$^{-3}$ of nitric acid and label it as X.
4.Suggest and describe a factor other than the concentration that can affect the rate of the above reaction.

  The enthalpy of neutralizatio+u3c o1rk-oudn for the reaction between sulfuric acid and potassium hydrouuo-1+ckr d o3xide can be determined experimentally.
$H_2SO_4$(aq)+2KOH(aq)→$K_2SO_4$(aq)+2$H_2O$(l)
A student recorded the temperature of 20.0 cm$^3$ of 0.500 mold m$^{-3}$ sulfuric acid every minute. At four minutes,25.0cm$^3$ KOH(aq) is added to the solution, stirred immediately, and temperature recorded for another four minutes. The results are represented in the graph below.



1.Calculate the lowest concentration of aqueous KOH that must be used to ensure it is in excess.
n$_{KOH}$=  mol;C$_{KOH}$=  mold m$^{-3}$
2.Use the graph above to estimate a value for the maximum temperature change, ΔT.
ΔT=  °C
3.State one assumption you made in part (b).
4.Identify the anomalous result and suggest a possible type and source of error.
5.In another experiment with the same reactants, the student measured the initial and final temperatures and presented their results below:
Initial Temperature (°C ± 0.1°C) 24.8 25.1 24.9
Final Temperature (°C ± 0.1°C) 26.4 26.6 26.4
5.1.Calculate the average change in temperature (ΔT) giving its percentage uncertainty.
Average=  °C
5.2.Use sections 1 and 2 of the data booklet to calculate the energy released and its uncertainty. You may assume that the only source of uncertainty is from the temperature change.
Energy released (q)=  J

1.State the complete balanced equation for the reaction between sulp qle,r3 +8 qb8 ltbm.i;w0ciqt;ogk /churic acid and coppegmri+lc,; loq t k8.qe w8qibt;3cb/ 0r (II) oxide.
2.State the complete balanced equation for the reaction between ethanoic acid and potassium carbonate.
3.Outline two ways to monitor the rate of reaction for reaction (b) above.

  The relationship between energy, E, an1 aauv) j/*ik08toj;bno tix ,d wavelength, λ, is shown according to the equation belo1ana,8tov*)/ ibx j;iju0to kw.
E=$\frac{hc}{λ}$


Which of the below statements are correct for the graph below representing E=$\frac{hc}{λ}$
?
I. Energy and wavelength are directly proportional
II.The units for the gradient are J m$^{-1}$
III.The y-intercept has the units J

  The feasibility of a reaction c 2nk uj3g h+g,w.9wjxproceeding spontaneously can be predicted using the. 9uw+nkgjxw,h 3g j2c following equation:
ΔG=−TΔS+ΔH.
Where ΔG is the change in Gibb’s free energy, ΔS is the change in entropy, and ΔH is the change in enthalpy.


1.When ΔG<0, a reaction can be described as spontaneous. Use the graph above to deduce the lowest temperature at which the reaction becomes spontaneous.
Read graph at ΔG=0,  K.
2.Calculate the gradient of the line and state its units.
3.Use your answer to part (b) to deduce the value and correct units for ΔS.
4.Use the graph to determine the value for ΔG when the temperature is raised to 675K.
Extrapolation of the line=  (kJ mol$^{-1}$)
5.Calculate a value for y-intercept=  and state the correct units {kJmol$^{-1}$|kJmol$^{-1}K^{-1}$}.

  The potential of a cell under non-stano 7hp )xg.9lw53gq8c7v--h ccwdx qys dard conditions can be calculated using th73gcyqdw5x.7 ghw--cos)9vqcx8p l he Nernst equation:
E=E$^θ$-$\frac{RT}{nF}$lnQ
For the graph below, which components of the equation represent the gradient and the y-intercept?

  The relationship betwee ( +m nw l+ckxoti7gf2ht(k(ih*:(njhn the concentration of a reactant, A, and the time, for a second-order reaction can be exikthmx+(k:gfhn n l(w(+cjh i7 2*ot(pressed using the equation below:
$\frac{1}{[A]}$=kt+$\frac{1}{[A]_0}$
Where [A] is the concentration of reactant A,[A] is the initial concentration of reactant $[A]_0$,t is the time in seconds,and k is a constant.


1.Calculate the gradient of the line and state the correct units.The number=  
2.Use the graph to determine $[A]_0$(also known as the initial concentration of A).
$[A]_0$=  mol dm$^{-3}$
3.Determine the time at which the concentration of A is equal to an eighth of its initial concentration.
[A]=  mol m$^{-3}$
(If you were unable to complete parts (a), and (b), you may use k=0.02, and $[A]_0$ =42).

  25.00 cm$^3$ of 0.100 mold m$^{-3}$$HNO_3$ was titrated against 0.200 mold m$^{-3}$$NaOH$.The volumes of NaOH delivered for the three trials 14.00 cm$^3$ ,14.05 cm$^3$ and 14.00 cm$^3$.
Which statement below best describes these results?