Aluminum hydroxide reacts with sulfuric acid as follows: 2Al(OH)3(s)+3H2SO4(aq)→Al2(SO4)3(aq)+6H2O(l)

1)How many moles of Al2(SO4)3 can form under these conditions?

2)How many moles of the excess reactant remain after the completion of the reaction?

Thank you!!

Using Ka values given in your textbook, design a buffered solution whose pH is 4.50.

a) what acid and salt will you use to make this buffer?

b) if you start with 0.20M solution of the weak acid, what inital concentration of the salt is needed?

c) how many grams of th salt would be needed to make 1.000 L of the buffer solution?

A Compartment A holds helium at pressure 5 atm, and compartment B holds argon at pressure 10atm. the partition between the gases is removed and the gases are allowed to mix. The mole fraction of helium in the mixture is 0.40 and the total volume of both compartments is 30.0 L . Temperature of helium and argon before and after mixing was 500K. Find volume of compartment A and B.

using a buret, add 1, 5, 10, and 15mL of standardized 0.0024 M K2CrO4 to each of four clean, dry 100-mL volumetric flasks and dilute to the 100 mL mark with 0.25 M NaNO3. Calculate the CrO4 2- concentration in each of these flasks

Given the values of ΔH∘rxn, ΔS∘rxn, and T below, determine ΔSuniv.

Predict whether or not each reaction will be spontaneous.

1.
ΔH∘rxn=− 118 kJ , ΔS∘rxn= 261 J/K , T= 294 K
ΔSuniv = ??? (J/K)

2.
ΔH∘rxn= 118 kJ , ΔS∘rxn=− 261 J/K , T= 294 K .
ΔSuniv = ??? (J/K)

3.
ΔH∘rxn=− 118 kJ , ΔS∘rxn=− 261 J/K , T= 294 K .
ΔSuniv = ??? (J/K)

4.
ΔH∘rxn=− 118 kJ , ΔS∘rxn=− 261 J/K , T= 565 K .
ΔSuniv = ??? (J/K)

Hydrogen gas (H₂), bromine gas (Br₂) and hydrogen bromide gas (HBr) are added to a 2.0 L flask such that the concentration of each are initially 1.5 *10^-2 M H₂, 1.5*10^-2 M Br₂, and 5.0 *10^-1 M HBr.

H_2(g) + Br_2(g) ⇌ 2HBr_(g) K_c=6.25*10¹ at 35 degrees C.

a.) Calculate the concentration of HBr once the system reaches equilibrium.

b.) calculate delta G standard for the above reaction.

The K_c value is correct as listed

Arsenic acid is a triprotic acid in water, ionizing in the following sequential steps: H3AsO4 + H2O <==> H2AsO4- + H3O+ Ka 5.5 x 10^-3 H2AsO4- + H2O <==> HAsO42- + H3O+ Ka 1.7 x 10^-7 HAsO42- + H2O <==> AsO43- + H3O+ Ka 5.1 x 10^-12 What is the approximate pH of a 0.80 M H3AsO4 solution?

Calculate how many milliliters of 0.1 M HCL should be added to how many grams of sodium acetate dihydrate (NaOAc*2H20, FM 118.06) to prepare 250 mL of 0.1 M buffer, pH=5.0

What is Aristotle’s “universal-particular argument” for the immateriality of the intellect? Recall matter as a principle of individuation. For Aristotle, is the brain an organ for intellect? Why does he say that all thought is ‘with images’ or imagination?

C. ΔH for Reaction of HCl_(aq) and NaOH_(s): CALCULATE DELTA H
Volume of HCl: 0.0550 L
Volume of water: 0.0450 L
Volume total: 0.100 L
Molarity of HCl: 1.95 M
Mass of NaOH: 3.44 g
ΔT for reaction C: 17°C

At a certain temperature the equilibrium constant, Kc, equals 0.11 for the reaction:

2 ICl(g) -----> I2(g) + Cl2(g)

What is the equilibrium concentration of ICl if 0.75 mol of I2 and 0.75 mol of Cl2 are initially mixed in a 2.0-L flask?

I got 0.56 for x, but now im not sure what to do. Please help. The answer is 0.45 M

One of the main functions of saliva is to buffer against acid from food and plaque, which contributes significantly to the formation of cavities. While there are several buffers in saliva, carbonic acid (H2CO3) has the highest concentration and has the greatest effect on pH.

(a) While the salivary concentration of carbonic acid stays at a fairly constant 1.3 mM, the level of bicarbonate (HCO3-) can vary with the rate that saliva flows from salivary glands. For low flow rates, the bicarbonate concentration is around 2 mM; for medium flow rates, it is 30 mM; and for high flow rates, around 60 mM. The pKa of carbonic acid at body temperature is 6.1. Assuming that the pH of Saliva is determined primarily by carbonic acid and bicarbonate, determine the pH of saliva for each of the three flow rates. The normal pH of saliva is about 6.3.

(b) The most prevalent bacterium in the mouth, streptococcus mutans, breaks down sugar and releases lactic acid (pKa = 3.86). If S. mutans has produced 10^-8 moles of lactic acid since your last swallow, what is the pH of your saliva? What would the pH be without the bicarbonate buffer? Assume that your mouth contains about 1 mL of saliva and that your saliva is flowing at a low rate.

(c) You take a drink of orange juice, and after you swallow, 0.5 mL remains in your mouth. What is the pH of your saliva if your mouth contains 1 mL of pure saliva, and if you model orange juice as 1.0 mM citric acid (pKa = 3.13; assume only one dissociation).

(d) Why do some toothpastes contain baking soda (sodium bicarbonate)?

A eco-conscious dad notices that we left the computer and light on from the last homework. After scolding us about the electrical bill, he turns them both off, and they eventually cool to the ambient temperature of 25 ^oC.

a) What is the total change in entropy for the computer chip (or bulb) for this cooling process? Find the total entropy change for the universe. (Recall that the chip is 50. g silicon, 20. g copper, and 65 g. polyvinyl chloride, initially running at a temperature of 75 ^oC.)

b) Find the specific entropy change for the light bulb in this cooling process. Calculate the specific entropy generated for the bulb. (The light bulb is initially filled with argon, an ideal gas, at a temperature of 65.0 ^oC a volume of 40. cm³ and a pressure of 103.8 kPa. Neglect the glass and metal comprising the rest of the light bulb.)

1) The half-life for the first-order decay of 14C is 5730 years. How long will it take for a sample to decay to just 10% of it’s initial amount?

At a certain temperature the K_sp of Ag₂SO₄ is 1.54 x 10^-5. What is the molar soliubility of silver sulfate in water in units of M (mol/liter).

In a titration of a 100.0mL 1.00M NH₃ solution with 1.00M HCl, what is the pH of the solution after the addition of 38.5 mL of HCl? K_b = 1.8 x 10^-5 for NH₃