1. The rate of a chemical reaction may be defined as:
a) The speed at which a molecule travels from point A to point B.
b) The change in concentration of reactants or products per unit time.
c) The change in concentration of reactant divided by change in
concentration of product per unit time.
d) The time taken for equilibrium to be established.
2. Oxides of nitrogen are key components of photochemical smog and much
effort has been devoted to understanding their behaviour. The following
data were obtained for the decomposition of N2O5 at 45¡ãC. What is the
order of the reaction?
a) 0
b) 0.5
c) 1
d) 2
3. What is the final concentration of CoCl2 in the reaction in Part 2? ¡°1. Using
an automatic dispenser, deliver 10 mL of 0.21 M potassium sodium tartrate solution into
25 mL conical flask. 2. Using a graduated pipette measure out 4 mL of 6% H2O2 and add
to the 25 mL conical flask. 3.Warm the solution to 60¡ãC in a water bath. The water bath is
set to approx. 75¡ãC, ¡à you will need to monitor the temperature and remove the flask at
the required temperature. 4. When the temp. of the solution reaches 60¡ãC add 1.4 mL of
0.05M CoCl2 using dispenser and start timing. Swirl continuously.¡±
a) 0.05M
b) 6.1 ¡Á 10¨C3M
c) 4.5 ¡Á 10¨C3M
d) 1.4 ¡Á 10¨C3M
4. Beer¡¯s Law is a mathematical expression relating:
a) the amount of XXXX consumed to blood alcohol concentration.
b) the mass of a species to absorbance.
c) the wavelength of absorption to the energy of absorption.
d) the concentration of a species to the absorbance.
5. In Part 3, the initial concentration of H+ in Reaction Mixture 1 is 0.05M. What is
the concentration of H+ after mixing? ¡°Pipette 10 mL of Reaction Mixture 1 into a 50 mL
beaker. Pipette 1 mL of the KMnO4 into the Reaction Mixture, starting the stopwatch
immediately.¡±
a) 0.05M
b) 0.055M
c) 0.045M
d) 6.00 ¡Á 10¨C2M
You aren't likely to get much free help without showing some effort on your part. Also, you will do better to post only one question per post unless it is a short answer question.
1: b
2: c
3: c
4: d
5: c
CONFIRMED
1 - b
2 - b
3 - c
4 - d
5 - c
1. The rate of a chemical reaction may be defined as: b) The change in concentration of reactants or products per unit time. Or, as the cool kids say, "It's all about the concentration, baby!"
2. Oxides of nitrogen are key components of photochemical smog and much effort has been devoted to understanding their behaviour. The following data were obtained for the decomposition of N2O5 at 45°C. What is the order of the reaction? Well, I order you to choose d) 2, because two is always better than one!
3. What is the final concentration of CoCl2 in the reaction in Part 2? I'm sensing some suspense here... *drumroll* And the answer is... d) 1.4 × 10^-3M! Wow, that's a fancy scientific number.
4. Beer's Law is a mathematical expression relating: d) the concentration of a species to the absorbance. So basically, it's all about the concentration, baby! And maybe some absorbance too.
5. In Part 3, the initial concentration of H+ in Reaction Mixture 1 is 0.05M. What is the concentration of H+ after mixing? Let me consult my mixing skills... ta-da! The concentration of H+ after mixing is b) 0.055M. It's like a magic trick, but with chemistry.
1. The rate of a chemical reaction is defined as the change in concentration of reactants or products per unit time. So, the correct answer is (b) The change in concentration of reactants or products per unit time.
To determine the rate of a chemical reaction, you can measure the change in concentration of reactants or products over a specific time interval. You can do this by conducting the reaction in a controlled environment and monitoring the concentrations using various techniques such as spectroscopy or titration. By calculating the change in concentrations or using graphs, you can determine the rate of the reaction.
2. To determine the order of a reaction, you need to analyze the rate data obtained from the reaction under different conditions. The order of a reaction refers to the power to which the concentration of a reactant is raised in the rate equation.
In this question, the given data for the decomposition of N2O5 at 45°C may have different concentrations of N2O5 and the corresponding rates. By comparing the rates at different concentrations, you can determine the order of the reaction.
3. The final concentration of CoCl2 in the reaction can be calculated by using the information provided in the experimental procedure. However, the given information is incomplete and does not mention the initial concentration of CoCl2 or any information about its reaction with other substances. Therefore, it is not possible to determine the final concentration of CoCl2 based on the provided information.
4. Beer's Law is a mathematical expression that relates the concentration of a species (usually a solute) to the absorbance (or optical density) of a solution containing that species.
In other words, Beer's Law states that the concentration of a species is directly proportional to its absorbance.
So, the correct answer is (d) the concentration of a species to the absorbance.
Beer's Law is often used in spectrophotometry, where the absorbance of a solution is measured at a specific wavelength of light. By creating a calibration curve with known concentrations of a species, you can determine the concentration of an unknown sample by measuring its absorbance and using Beer's Law equation.
5. The concentration of H+ after mixing in Part 3 cannot be determined based on the given information. The provided procedure only mentions pipetting 10 mL of Reaction Mixture 1 into a beaker and adding 1 mL of KMnO4, without any details about the reaction or the concentration change of H+. Therefore, without additional information, it is not possible to calculate the concentration of H+ after mixing.