The balanced equations for this reaction shows that the molar ratio of magnesium reacted to hydrogen gas produced is 1:1. Therefore, by determining the mass of magnesium that reacts and the number of moles that this mass is equal to, you will also be able to determine the number of moles of hydrogen gas produced. The volume of hydrogen gas produced will be measured directly on the scale of a gas-measuring tube. The gas laws of Boyle and Charles will be used to correct this volume, measured under laboratory conditions, to the volume the sample of gas would occupy at STP. The collected data (number of moles and volumes at STP) will be used to calculate that molar volume of the hydrogen gas.
The half reactions for this system are: Oxidation of 〖Fe〗^(2+): 〖Fe〗^(2+)→ 〖Fe〗^(3+)+1e^- Reduction of 〖MnO〗_4^-: 〖MnO〗_4^-+8H_3 O^++5e^-→ 〖Mn〗^(2+)+12H_2 O Which produces the following overall equation: 〖MnO〗_4^-+8H_3 O^++5〖Fe〗^(2+)→5〖Fe〗^(3+)+〖Mn〗^(2+)+12H_2 O Equilibrium is initially obtained at a very slow rate, therefore the titration is carried out in the presence of excess sulphuric acid (H_2 〖SO〗_4) at a high temperature; in order to drastically increase the rate at which equilibrium is attained. Potassium permanganate acts as its own satisfactory indicator since the reagent 〖MnO〗_4^- anion appears to be an intense purple colour while the product 〖Mn〗^(2+) cation has a colourless appearance. However, the end point must be read quickly as the permanganate end point gradually fades due to the 〖MnO〗_4^- reacting with the 〖Mn〗^(2+) that was formed during the titration. When performing the titration, one must be cautious as side reactions can occur and these side reactions must be prevented using appropriate chemical measures. If an insufficient amount of acid was
We expect Pentane to be the most ideal because it’s boiling point is the furthest away from the boiling point of water. To test our hypothesis, we used heat to vaporize each gas, an ice bath to cool the gases down and measured the condensed liquid gas to calculate each gas’s constant. Methods: In this experiment, we first measured the mass of an empty flask using
If the reaction is first order, its graphical representation is seen as ln[A] (natural log of concentration) vs. time, and the slope of its like is also the negative rate constant. Finally, for a second order reaction the graph is shown as 1/[A] (inverse of concentration) vs. time, and the slope of its given line is the positive rate constant. By understanding the rate law and finding the value of the correct rate constant with respect to the order of the reaction, one can determine the half-life of the crystal violet. This is because the crystal violet undergoes a decay reaction with the sodium hydroxide. According to Beer's Law, the absorbance of crystal violet is proportional to its concentration.
Also, the more stable the free radical that is left behind, the weaker its C-H bond strength will be. The difference between the bromine and chlorine product ratios can be partially explained by the Hammond postulate, which states that species with similar energy levels also have more similar structures and react more quickly and less selectively. In the experiment, five different hydrocarbons were tested to measure the rate of reaction with the addition of bromine. Two trials were done, one with the test tubes containing the hydrocarbons and added bromine sitting directly under a lamp, and another with the test tubes in a closed, dark space. Both trials contained a
3) Write equations to indicate what you consider to have happened in each case in which there was precipitate formed. Use ions to represent the species in the reacting solutions, but for those products that were precipitates write a formula for the compound. Place (aq) after those species in solution and (s) after the precipitates. Be sure to write the equations so that both atoms and charge are conserved. For example: Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq) ( AgCl(s) + Na+(aq) + NO3-(aq) 4) Rewrite the equations, leaving out the ions not involved in the reaction (spectators).
It is quite like ethylene glycol. It has a boiling point of 188.2°C and a melting point of -59°C(7). What are the specific heat capacities of glycerol, water and olive oil? Glycerol: 2.5 J/g/°C (4) Water: 4.18 J/g/°C (2) Olive oil: 2.0 J/g/°C (3) How do the properties of these three liquids compare to the properties of the liquids used in radiators? Glycerol has some useful properties.
(4.) What is the total pressure(mmHg) of a gas mixture containing argon gas at 0.25 atm, helium gas at 350 mmHg and nitrogen gas at 360 torr. (Hint: use Dalton’s Law of Partial Pressures). *Dalton’s Law: a gas law stating that the total pressure exerted by a mixture of gases in a container is the sum of the partial pressures that each gas would exert alone. *Partial Pressure: the pressure exerted by a single gas in a gas mixture.
For help, look on p. 50 in the Ultimate Chemical Equations Notebook for a similar reaction. • Discuss briefly how stoichiometry works and give a simple mole to mole example. • Give the Ideal Gas Law and the value of R (0.0821 L atm/K mol) • For extra credit, look up the molecular structure of the pigment in red cabbage and draw it. Prelab Questions (write the question, show all work, box answers): 1. How many moles of hydrogen gas can be produced when 10.0 g of Zn react with excess HCl?
The melting point of paradichlorobenzine is approximately 53.5 °C but my graph illustrates it at 51°C. ( (Note this is due to the different atmospheric pressures and concentration of paradichlorobenzine which causes some minor variation.) 5. I can conclude that both the melting and boiling points of a pure substance are the (almost) the same. This is due to the fact that pure substances (unlike mixtures) have definite composition.