Use the half reaction method to balance each of the following oxidation-reduction reactions. Identify the oxidizing agent and the reducing agent.

A) Cu(s) + Ag+(aq) ---> Ag(s) + Cu2+

B) Al(s) + I2(s) ---> AlI3(s)

C) Pb(s) + Fe3+(aq) ----> Pb2+(aq) + Fe(s)

What is the pH of a 0.250 M NaOCl solution? Kb = 3.4 x 10-7

what makes the noble gases "noble"?

Polonium crystallizes with a simple cubic structure. It has a density of 9.3 g/cm^3 , a radius of 167 pm, and a molar mass of 209 g/mol .
Estimate Avogadro's number (the number of atoms in one mole).

A hydrogen electron in the ground state absorbs a 92.3157 nm photon to reach a higher excited state (a), and then emits two photons, one with 1.75777 x 10^-20 J of energy to reach an intermediate state (b), and one with wavelength 1005.22nm as it falls back to a lower excited state (c). Determine the three energy levels (a,b,c) of this particular electron.

-- I can calculate the formula mass but get confused with the various conversions between different types of units. I have the correct answers but I am trying to learn how to work through the problems to get the correct answer.

10) A sample of talc, Mg3Si4O10(OH)2, has a mass of 0.664 g. Calculate the number of mmoles of Mg3Si4O10(OH)2.

11) A sample of gypsum, CaSO4•2H2O, has a mass of 22 g. Calculate the number of moles of CaSO4•2H2O.

12) A sample of potassium dichromate, K2Cr2O7, has a mass of 578 Gg. Calculate the number of moles of K2Cr2O7.

13) A pure sample contains 660 moles of potassium dichromate, K2Cr2O7. What is the mass of the sample?

14) A pure sample contains 3.0 x 10-8 moles of gypsum, CaSO4•2H2O. What is the mass of the sample in units of ng?

15) A pure sample contains 8.8 x 10-2 moles of talc, Mg3Si4O10(OH)2. What is the mass of the sample?

16) A pure sample contains 1.5 moles of ammonium carbonate, (NH4)2CO3. What is the mass of the sample?

The answers are

10) 1.75 mmoles Mg3Si4O10(OH)2

11) 0.13 moles CaSO4•2H2O

12) 1.96 x 109 mol K2Cr2O7

13) 1.94 x 105 g K2Cr2O7

14) 5165 ng CaSO4•2H2O

15) 33.4 g Mg3Si4O10(OH)2

16) 144.1 g (NH4)2CO3

TYPED RESPONSE ONLY WITH AT LEAST 1 REFERENCE:

List four factors that can shift the position of an equilibrium. Only one of these factors can alter the value of the equilibrium constant. Which one is it?

What is the percent dissociation of 1 L of 0.1000 M acetate buffer at pH 4.76 after the addition of 77.76 mL of 0.3201 M HClO4 ?

In a constant-pressure calorimeter, 60.0 mL of 0.310 M Ba(OH)2 was added to 60.0 mL of 0.620 M HCl. The reaction caused the temperature of the solution to rise from 22.61 °C to 26.83 °C. If the solution has the same density and specific heat as water (1.00 g/mL and 4.184 J/g·°C, respectively), what is ΔH for this reaction (per mole of H2O produced)? Assume that the total volume is the sum of the individual volumes.

1) You are a research scientist studying a novel enzyme X, and you want to characterize this new enzyme. You measure the velocity of the reaction with different substrate concentrations and get the following data:

a) Graph the above data. From the graph, estimate KM and Vmax (Michaelis-Menten Plot)

b) Use Lineweaver-Burk plot to calculate Km and Vmax. Show all equations and calculations.

c) You decide to do this experiment again, but this time with only one third of the enzyme X concentration used in the first experiment. Draw a new graph on the same graph that you did the first graph on. Estimate Km and Vmax from the new graph.

Sodium fluoride and lead nitrate are both soluble in water. If 0.0946 g of NaF and 0.362 g of Pb(NO₃)₂are dissolved in sufficient water to make 1.50 L of solution, will a precipitate form? How do you know if there should be a precipitate or not? What is the chemical formula for the possible precipitate? The Ksp for lead fluoride is 3.7 x 10^-8.

Explain the spectral differences between the spinach and the Cordyline fruticose leaves.

What determines the leaf color in plants? Provide a structure and of the molecule and explain why green is the predominant color.

Why do deciduous trees change color in the fall (biochemical explanation). Provide a molecule responsible for yellow and one for red color. Why are these molecules necessary in addition to the chlorophyll?

Here we have a Radioactive Thermoelectric Generator (RTG) that is powered by Plutonium 238 (²³⁸Pu). The RTG produces 1400 Watts. ²³⁸Pu decays by alpha-particle emission. The alpha-particle has 5.593 MeV of kinetic energy. The half life (t_1/2) of ²³⁸Pu is 87.7 years.

a) Write the nuclear reaction for ²³⁸Pu decay

b) Assume all of the kinetic energy is converted to heat. How much ²³⁸Pu (in grams) must be present to produce 1400 Watts of power?

1. A student prepares a 250.0 mL solution using 41.7 grams of potassium nitrite. They then take 29.9 mL of this solution and dilute it to a final volume of 250.0 mL. How many grams of potassium nitrite are in a 36.2 mL sample of this final diluted solution?

2.

Part A

A beaker with 195 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 4.50 mL of a 0.430 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.740.