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What were the expected and observed results of Geiger and Marsden's alpha particle experiment? Explain with the help of suitable diagrams
Analyze the three chemical equation below then answer th3 corresponding guide question
2N2O(g) → 2N2(g) + O2(g)
SO2Cl2(g) → SO2(g) + Cl2(g)
O + H2 O → 2OH
Guide questions
1. How will you describe the three chemical equations?
2. What can you say about the reactants of the three chemical equations?
3. What type of chemical reaction is displayed by the three chemical equations?
Write the thermochemical equation for the following reactions that occur at constant pressure.
1. Combustion of hexane, C6H12 to carbon dioxide gas and water, releases 3923.9kJ of heat.
2. Reaction between solid phosphorous, P4 and oxygen gas, produces P306 and 1640.1kJ of heat.
3. One mole ammonium nitrate (NH4NO3) dissolves in water to produce aqueous ammonium ions and nitrate ions accompanied by the absorption of 28.1 kJ of heat.
4. Formation of carbon dioxide gas from carbon (graphite) and oxygen yields 393.5 kJ of heat.
Salt is often used to melt ice and snow on roads in the winter and the temperature right now is -4.500°C. How much NaCl (complete dissociation) would be necessary to melt 1000kg of ice by bringing down the freezing temperature to -4.500°C?
So, I have a question on my homework that I have 0 idea how to do it, do you think you could tell me how to do it and give me the answer so I am prepared for future similar questions? Thank you, here is the question:
What mass of Al(OH)2 is required to make 15.6 L of a solution with a pH of 10.72?
with carbon dioxide, what phase change takes place when pressure increases from atm to 10 at -40C?
Question 2
a) Table 1 shows results of 12 measurements of activation energy (Ea) for some reaction. The literature value of the activation energy for this reaction is 38.942 kJ/mol.
Table 1: Measurement of Activation energy
Measurement Ea (kJ/mol)
1 38.542
2 38.751
3 39.016
4 38.768
5 38.943
6 38.426
7 39.124
8 38.546
9 38.864
10 38.687
11 38.579
12 38.798
Do these results differ significantly from the literature value? [15 Marks]
b) How can a research problem be justified for a particular research? [10 Marks]
- A gas system with constant pressure has change in internal energy of 240 J. Heat was lost to the surroundings and 150 J work was done to the surroundings as well. How many calories of heat was lost?
Question 2
The silver concentration in a sample of photographic waste was determined by AAS. Table 3 shows the results obtained. Is the calibration data linear? Plot the calibration curve. [25 Marks]
Table 3: Determination of silver concentration by AAS
Added Ag: µg added per ml of original solution 0 5 10 15 20 25 30
Absorbance 0.32 0.41 0.52 0.60 0.70 0.77 0.89
Question 1
Table 2 gives the recovery of bromide from spiked samples of vegetable matter, measured by Gas-liquid chromatographic method. The same amount of bromide was added to each specimen.
Table 2: Recovery of bromide from spiked samples of vegetable matter
Tomato 777 790 759 790 770 758 764
Cucumber 782 773 778 765 789 797 782
a) Test whether the recoveries from the two vegetables have variances which differ significantly. [10 Marks]
b) Test whether the mean recovery rates differ significantly.
