In June 2024
Search & Filtering
Predict whether the entropy change of the system in each of the following is positive or negative.1. O2(g) → 2O(g)2. N2 (g, 10 atm) → N2 (g, 1atm)3. 6CO2(g) + 6H2O(g) → C6H12O6(g) + 6O2(g)4. 2 H2 (g) + O2 (g) → 2 H2O (l)5. NH4Cl (s) → NH3(g) + HCl (g)
Given the reaction:
2 NaOH + H2SO4 ⟶
Na2SO4 + 2 H2O
How many moles of sodium sulfate (Na2SO4) reproduced when 9.9 moles of sodium hydroxide (NaOH) are reacted with excess sulfuric acid?
1 Calculate the frequency and wavenumber of an X-ray beam with a wavelength of 2.56Å.
2 Calculate the wavelength in cm and energy in joules of a photon of light with a frequency of 250MHz.
3 Guanosine has a maximum absorbance of 275nm. Ɛ= 8400 M-1 cm-1 and path length is 1cm, using a spectrophotometer, A was found to be 0.70. What is the concentration of guanosine?
4 The molar absorption coefficient of a glycogen-iodine complex is 0.20 at a light of 450nm. What is the concentration when the transmission is 40% in a 2cm cuvette?
10. Consider 25.0mL of 0.100M HA (HA is a fictional acid), for which Ka=1.00x10-5, titrated with 0.0500M NaOH solution. What is the initial pH before adding any titrate? (4 marks)
11. 50.0mL of 0.185M Sr(OH)2 is reacted with 35.0mL of a solution containing 0.130g of HCl. a. Calculate the pOH resulting from the mixture. (8 marks) b. Suggest an indicator that will be effective for this incomplete titration and explain your choice. (2 marks)
8. Choose the most correct indicator given: 0.1L of a 1M HCl solution is added to a 0.1L of a 1.01M NaOH solution. (8 marks). Show your work for full marks.
a. Bromocresol green-the solution is blue
b. Phenol red- the solution is yellow
c. Alizarin yellow-the solution is dark orange
d. Phenolphthalein- the solution is colourless
9. Would it take more 0.1M HCl or 0.1M H2SO4 to neutralize 30mL of NaOH? Explain how you know. (2 marks)
6. Determine if the pH at the equivalence point is 7, >7 or <7 for the following titrations: (3 marks)
a. NH3 titrated with HCl
b. Ba(OH)2 titrated with HCl
c. HF titrated with NaOH
7. In a titration, 34.8 mL of 0.115M HNO3 were required to neutralize 25mL of solution of Ca(OH)2. What was the original concentration of the Ca(OH)2 solution? Include the neutralization equation for full marks. (4 marks)
4. A solution of HF contains 12 grams in 500.0mL. (5 marks)
a. Find [H+]. Make sure to show the ionization equation (with water)
. b. Calculate the pH of the above solution.
5. Predict the products of the following neutralization reactions (be sure to balance the equation and include states as well). (2 marks) a. HCl(aq) + Mg(OH)2(s) b. H3PO4(aq) + KOH(s)
The decomposition of N2O5 is an important process in tropospheric chemistry. The half-life
for the first order decomposition of this compound is 2.05X104 s. How long will it take for a
sample of N2O5 to decay to 60% of its initial value?
For the following reaction, 108 grams of silver nitrate are allowed to react with 23.6 grams of copper .
silver nitrate(aq) + copper(s) copper(II) nitrate(aq) + silver(s)
What is the maximum amount of copper(II) nitrate that can be formed? grams
What is the FORMULA for the limiting reagent?
What amount of the excess reagent remains after the reaction is complete? grams
calculate the time required to deposit 56g of silver from a silver nitrate(AgNO3)solution using a current of 4.5amper
-
![Help me with my assignment!]()
Who Can Help Me with My Assignment
There are three certainties in this world: Death, Taxes and Homework Assignments. No matter where you study, and no matter…
-
![How to finish assignment]()
How to Finish Assignments When You Can’t
Crunch time is coming, deadlines need to be met, essays need to be submitted, and tests should be studied for.…
-
![Math Exams Study]()
How to Effectively Study for a Math Test
Numbers and figures are an essential part of our world, necessary for almost everything we do every day. As important…
