goldserval389

Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. (Ka(HF)= 3.5x10^-4)

a. 0.15 M HF

How many liters of NH₃, at STP, will react with 19.5 g O₂ to form NO and H₂O? You must show all of your work to receive credit. (2 points)

What is the formula of ammonium carbonate?

What is NaCl?

How many atoms of iron in 3.215g of Fe2(SO4)3?

A mass of 22.8 g of an unknown gas exerts a pressure of 0.912 atm at 78°C in a 10.0 L flask. What is the molar mass of the gas?

A) 1.56 g/mol

B) 16.0 g/mol

C) 44.0 g/mol

D) 72.0 g/mol

An 80.0-gram sample of gas was heated from 25°C to 225°C. During this process, 346 J of work was done by the system, and its internal energy increased by 8455 J. What is the specific heat of the gas?

A 0.1046 g diprotic organic acid required 23.47 mL of 0.1072 M standard KOH to reach the first end point. What is the molecular weight of the acid.

A compound containing carbon and nitrogen has a composition of 46.16% carbon and 53.84% nitrogen by mass. A solution prepared by dissolving 3.912 g of this compound in 20.00 g of carbon tetrachloride, CCl₄, produces a solution that boils at 95.63°C. What is the molecular formula of the compound? (K_b for CCl₄ is 5.03°C/ m, and pure CCl₄ has a freezing point of 76.72°C.)

A mixture of hydrocarbons contains 36.6 % heptane, C₇H₁₆, 13.4 % nonane, C₉H₂₀, and 50.0 % octane, C₈H₁₈. The mixture is combusted in an excess of oxygen. What mass of CO₂ is generated from the combustion of 11.0 kg of the mixture?

A student experiment involved burning 1.04 g of C(s) in a calorimeter. The student found that burning the carbon released enough heat to increase the temperature of 1.00 kg of water from 12.00°C to 19.36°C. Calculate the amount of heat released by the carbon (assume all the heat went into the water).

A certain light has an energy of 4.86×10^-20 J. What is the wavelength of this light?

What volume of 0.2500 M cobalt (III) sulfate is required to react completely with

a. 25.00 ml of 0.0315 M calcium hydroxide?

b. 12.50 ml of 0.1249 M potassium phosphate?

1. A graduated cylinder, when filled to the 40.00 mL mark with water (density 1.00 g/mL) and capped with a stopper, had a mass of 352.05 grams. The same cylinder had a rock of mass 37.40 grams placed into it and was re-filled to the 40.00 mL mark with water. The same cylinder, when capped (with the same stopper) now had a mass of 383.95 grams. What is the density of the rock?

4. (a) In an industrial process, a fuel-air mixture occupying a volume of 500 L is fitted with a piston. When the mixture is ignited at a constant pressure of 600mmHg, 2.0 kJ of energy is released. To what volume the mixture would have expanded if all the energy released is converted as work done by the system to push the piston?  

A piece of indium with a mass of 16.6 g is submerged in 46.3 cm³ of water in a graduated cylinder. The water level increases to 48.6 cm³. The correct value for the density of indium from these data is:

A) 7.217 g/cm³

B) 7.2 g/cm³

C) 0.14 g/cm³

D) 0.138 g/cm³

E) more than 0.1 g/cm³ away from any of these values.

A 2.00-mole quantity of SO₂Cl₂ was placed in a 2.4L container. Initially, there are no products in the container. At equilibrium, it was determined that 49.0% of the SO₂Cl₂ had dissociated. What is the value of the equilibrium constant under these conditions?

(A) 0.3923203

(B) 0.196

(C) 1.96

(D) 1.8831137

(E) 0.9415686

QUESTION 7

Consider the following specific heats of metals.

If the same amount of heat is added to 25.0 g of each of the metals, which are all at the same initial temperature, which metal will have the highest temperature?

A 0.5895-gram sample of impure magnesium hydroxide is dissolved in 100.0 mL of 0.2050 M HCl. The excess acid then needs 19.85 mL of 0.1020 M NaOH for neutralization. Calculate the percent by mass of magnesium hydroxide in the sample, assuming that it is the only substance reacting with the HCl solution.

What is the OH^- ion concentration in 5.2×10^-4 M of HNO₃.

How many moles of water are formed when 50 mL of NaCl and 50 mL of NaOH are combined in a coffee cup calorimeter? (Molarity of solutions = 0.1 M)

What is the size of nanoparticles?

A certain soft drink is bottled so that a bottle at 25°C contains CO₂ gas at a pressure of 4 atm over the liquid. Assuming the partial pressure of CO₂ in the atmosphere is 4.0×10^-4 atm, calculate the equilibrium concentration of CO₂ in the soda after the bottle is opened. The Henry’s Law constant for CO₂ in an aqueous solution is 3.1×10^-2 mol/L·atm at 25°C.

You have solutions of 0.200 M HNO₂ and 0.200 M KNO₂ (K_a for HNO₂ = 4.00 × 10^–4). A buffer of pH 3.000 is needed. What volumes of HNO₂ and KNO₂ are required to make 1 liter of a buffered solution?

A) 500 mL of each

B) 286 mL HNO₂; 714 mL KNO₂

C) 413 mL HNO₂; 587 mL KNO₂

D) 714 mL HNO₂; 286 mL KNO₂

E) 587 mL HNO₂; 413 mL KNO₂

Title: “IDENTIFY THE LIMITING REACTANT/REAGENT PRACTICE” 

5.87 g of Mg(OH)₂ reacts with 12.84 g of HCl

Hydrogen sulfide gas is a poisonous gas with the odor of rotten eggs. It occurs in natural gas and is produced during the decay of organic matter, which contains sulfur. The gas burns in oxygen as follows:

2H₂S(g) + 3O₂(g) → 2H₂O(l) + 2SO₂(g)

Calculate the standard enthalpy change for this reaction using standard enthalpies of formation.

Theophylline is a pharmaceutical drug that is sometimes used to help with lung function. You observe a case where the initial lab results indicate that the concentration of theophylline in a patient's body decreased from 2.0×10^-3 M to 1.0×10^-3 M in 24 hours. In another 12 hours the drug concentration was found to be 5.0×10^-4 M. What is the value of the rate constant for the metabolism of this drug in the body?

A piece of plastic weighing 1.157 g has a volume of 1.48 cm³. A piece of wood has the same volume but weighs 3.85 g. The density of liquid X is 0.765 g/mL and the density of liquid Z is 1.13 g/mL. The two liquids are immiscible. If the plastic and wood are added to the two liquids, what is the order of layers from top to bottom in the container?

Suppose that you have 165 mL of a buffer that is 0.220 M in both propanoic acid (C₂H₅COOH) and its conjugate base (C₂H₅COO⁻). Calculate the maximum volume of 0.330 M HCl that can be added to the buffer before its buffering capacity is lost.

The equilibrium constant Kp for the oxidation of sulfur dioxide into sulfur trioxide is 5.6×10^-4 at 3500°C. If the equilibrium partial pressures of SO₂ and SO₃ are 0.64 atm and 0.58 atm, respectively, what is the partial pressure of O₂ in the system?

You find a penny (assume to be pure copper with a specific heat of 0.385 J/g°C) in the snow which has a temperature of -10.0°C. How much heat, in Joules, is absorbed by the penny as it warms to body temperature, 35.0°C? The mass of the penny is 3.10 g. Report answer to 3 significant figures and use + or - to indicate the direction of energy flow. Assume the unit to be Joules.

A student prepared a stock solution by dissolving 10.0 g of KOH in enough water to make 150 mL of solution. She then took 15.0 mL of the stock solution and diluted it with enough water to make 65.0 mL of a final solution. What is the concentration of KOH for the final solution?

What is the osmotic pressure of a solution prepared at 25.0°C by dissolving 50.0 mg of a protein with a molar mass of 3.60×10³ g/mol in enough water to form 50.0 mL of solution?

a.) 0.00679 atm

b.) 0.000340 atm

c.) 0.000570 atm

d.) 6.79 atm

The half-lives of radioisotopes are given below.

• arsenic-74 - 18 min
• iodine-131 - 8 min
• phosphorus-32 - 14 min
• chromium-51 - 28 min

If the initial amount of chromium-51 is 133 mCi, how much chromium-51 is left in the body after 84 days?(Answer in mCi)

How many moles of Ca are 3.01×10²³ atoms of calcium?

A) 1.81×10⁴⁷ mol

B) 0.500 mol

C) 1.00 mol

D) 3.01×10²³ mol

E) 3.01 mol

a.) Balance the equation

b.) How many kilograms of thionyl chloride remove 216 kilograms of water?

What is the name this compound?

Lysozyme is an enzyme that cleaves bacterial cell walls. A sample of lysozyme extracted from egg white has a molar mass of 13,930 g/mol. A quantity of 0.100 g of this enzyme is dissolved in 152 g of water at 25°C. Calculate the vapor-pressure lowering, the depression in freezing point, the elevation in boiling point, and the osmotic pressure of this solution. (The vapor pressure of water at 25°C is 23.76 mmHg.).

The rate of diffusion of two gases A and B is in the ratio of 1: 4 and that of B and C in the ratio of 1:3. The rate of diffusion of C with respect to A is

1.A gas sample has a volume of 235 mLmL at 24 ∘C. What is its volume at 98 ∘C?