what is the concentration of Cd2+ in a 0.010 M Cd(NO3)2 solution that is also 1.0 M NH3? For Cd(NH3)4^2+, Kf=1.0x10^7

1. If we use symbol U_sys to represent the energy (also referred as internal energy) contained in the system, what is a reasonable symbol to represent the energy of the surroundings? Provide an expression relating the total energy of the Universe, U_univ to the energy of the system and energy of the surroundings? Explain your answer

2. Now consider the system undergoes a process, let DU_sys represent the change in system’s energy, DU_univ represents the change in energy of the universe. Provide an expression for DU_univ in terms of energy change of the system and the surrounding. Explain your answer.

3. Consider your answer in (2), what would be the reasonable sign for DU_univ? Explain.

4. Consider your answer in (2), what would be the reasonable sign for DU_sys? Explain

5. Let q and w represent two ways to exchange energy between system and surrounding. What is a reasonable expression that relates the internal energy change DU_sys with q and w?

6. Consider burning of propane gas (propane and oxygen gases are our interested system), is this an exothermic reaction? What is the sign of q? what is the sign of DU_sys ? Describe in your own words what happened to the internal energy of the system?

7. Identify each energy exchange as heat or work and determine the sign of heat or work is positive or negative

(a) An ice cube melts and cools the surrounding beverages (ice cube is the system here)

(b) A metal cylinder is rolled up a ramp (the metal cylinder is the system)

(c) Steam condenses on skin causing a burn (the condensing steam is the system)

8. Consider a closed container that contains some hydrogen gas (H₂) and oxygen gas (O₂). These gases reacted (burned) and formed water vapor.

(a) Write a balanced chemical equation to represent this process (reaction)

(b) Do you expect this is an exothermic or endothermic reaction? What is the sign of q?

(c)What is the sign of internal energy change DU for this reaction?

(d) List the types of energy stored in the system before and after reactions. How do you explain the sign of internal energy DU observed in part (c)?

Consider the formation of solid Ba(IO 3 ) 2 from the mixing of 7.5mg of barium chloride being dissolved in 500ml of 0.023M sodium iodate.

a) How much solid barium iodate form

b) What is the concentration of barium ions and iodate ions at equilibrium?

How do you would prepare a 2.00 M solution of sodium chloride?

What is the net charge of the dipeptide Glu-Ala at pH=4.1, given the following data for the individual amino acids:

Glu: pKa1= 2.1; pKa2= 9.5; pKaR= 4.1
Ala: pKa1 = 2.3; pKa2 = 9.9

#1. Show work

Consider a new alloy that is made by mixing the following three metals in the given proportions, by

mass: 55.75% aluminum; 33.50% lead; 10.75% magnesium

The new alloy is sold as cubes with a total mass of 22.75 g. Calculate the density of a

single cube of this alloy. (Hint: Assume that the volumes of the metals are additive

and assume that the temperature of all the metal samples and the alloy remains

constant. You will need to look up the density of each of the pure metals)

Can you please write a written detailed procedure (like paragraph not a chart please) for the two experiments:

1- qualitative analysis of cation group 1

2- qualitative analysis of cation group 2

125.0-mL aliquot of 0.124 M diprotic acid H2A (pK1 = 4.03, pK2 = 8.06) was titrated with 1.24 M NaOH. Find the pH at the following volumes of base added: Vb = 0.00, 1.80, 6.25, 11.50, 12.50, 13.50, 18.75, 24.00, 25.00, and 28.00 mL. (Assume Kw = 1.01 ✕ 10−14.)

A 0.400 M solution of weak base has a pH of 9.85. What is the base hydrolysis constant, Kb for the weak base?

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL 21) of aqueous formic acid requires 29.80 mL of 0.0567 M NaOH? Ka =1.8 × 10-4 for formic acid.

A) 2.46 B) 8.12 C) 11.54 D) 5.88

A student started a synthesis of alum with 3.4x10^-2 mole aluminum:

2Al (s) + 6h2O (I) + 2KOH (aq)------> 2K[Al(OH)4] (aq) + 3H2 (g) (1)

2K[Al(OH)4] (aq) + H2SO4 (aq) ------> 2Al(OH)3 (s) +2 K2SO4 (aq) + 2H2O (I) (2)

2Al(OH)3 (s) + 3H2SO4 (aq) ---------> Al2(SO4)3 (aq) + 6H2O (3)

Al2(SO4)3 (aq) + K2SO4 (aq) + 24 H2O---------> 2KAl(SO4)2 12H2O (4)

a) What theoretical yield of alum, in gram, would be produced from 3.4x10^-2 mole of aluminum?

b) A student obtained 12.4 g alum from the synthesis. If the theortical yield was 19.6 g, what was the percent yield?

Why does the Zaitsev product always form in an E1 reaction regardless of the bulkiness of the base?