Ammonia reacts with oxygen according to the equation: 4NH3(g)+5O2(g)→4NO(g)+6H2O(g) ΔHrxn=-906 kJ Part A Calculate the heat (in kJ) associated with the complete reaction of 284 g of NH3. Express your answer with the appropriate units.

What happens to the pressure of a gas when T is halved and volume is doubled

1.It is ¼ of its initial value

2.It is 4 times its initial value

3.It is ½ of its initial value

4.It is 2 times its initial value

5.It is ¾ of the initial value

6.It remains the same.

Please show work

A laser puts out 4.4 W of continuous power at a wavelength of 532 nm. The diameter of the laser beam is 5.1 mm

If the laser is pointed toward a pinhole with a diameter of 1.0 mm, how many photons travel through the pinhole per second? Assume that the light intensity is equally distributed throughout the entire cross-divisional area of the beam. (1 W = 1 J/s)

A 2.85 g lead weight, initially at 11.0 ∘C, is submerged in 7.43 g of water at 52.2 ∘C in an insulated container. You may want to reference ( pages 349 - 355) section 10.4 while completing this problem. Part A What is the final temperature of both the weight and the water at thermal equilibrium? Express the temperature in Celsius to three significant figures. T = ∘C

A sample containing 4.10 g of O2 gas has an initial volume of 21.0 L . What is the final volume, in liters, when each of the following changes occurs in the quantity of the gas at constant pressure and temperature?

A) A sample of 0.300 mole of O2 is added to the 4.10 g of O2 in the container. Express the volume in liters to three significant figures.

B). A sample of 2.20 g of O2 is removed from the 4.10 g of O2 in the container. Express the volume in liters to three significant figures.

C). A sample of 2.20 g of O2 is added to the 4.10 g of O2 gas in the container. Express the volume in liters to three significant figures.

Calculate the solubility (in g·L–1) of CuBr(s) (Ksp = 6.3× 10–9) in 0.57 M NH3(aq).

calculate the freezing point of water (Kf= 1.86 C/m) for an ideal solution of sodium phosphate which has a concetration of 3.25 m .

How many of the following responses are true?

1. A primary alkyl halide will tend to react through an SN2 mechanism because there is little hindrance to backside attack and a primary carbocation is not very stable
2. 3-bromo-3-methylpentane will undergo substitution through an SN2 mechanism
3. If R-2-bromopentane is allowed to react with OH- the product will be S-2-pentanol
4. SN1 leads to a racemization of sterechemistry due to the nucleophile attacking from the backside and the leaving group leaving
5. SN2 leads to a racemization of sterechemistry due to the nucleophile attacking from the backside and the leaving group leaving

I thought 1, 3, and 4 were right, but my answer was wrong! Please help!

The Hohenberg-Kohn theorems show a one-to-one mapping between the density and the molecular Hamiltonian. What information is contained in the Hamiltonian and, conceptually, how can this information be extracted from the density?

Calculate the pH after adding 10.00 mL of 0.15 M HCl to 50 mL of the ammonia/ammonium ion buffer solution with a ph of 4.82

Describe the biochemical mechanism of kidney damage of untreated diabetic people

The alkalinity of natural waters is usually controlled by OH- , CO3 2- , and HCO3 - , which may be present alone or in combination. Titrating a 100.0 mL sample to a pH of 8.3 requires 18.70 mL of a 0.0281 M solution of HCl. A second 100.0 mL aliquot requires 48.20 mL of the same titrant to reach a pH of 4.5. Calculate the concentrations of CO3 2- and HCO3 - in ppm.

A sample of metal with a mass of 350 g is heated to 100 degrees celcius and dropped into 400 g of water at 21.4 degrees celcius. The temp of the water rises to 28.0 celcius. Assume no heat is lost to the environment.

What is the amount of heat gained?

What is the specific heat of the metal?

Find the fraction of dissociation, α of an aqueous 0.400M triethylamine [(CH₂CH₃)N] solution.

The total mass of DNA in the body is 50.0 g. If the number of nucleotides in ONE STRAND of DNA is approximately 3.0 x 10⁶ , and the average length of a single nucleotide is 0.34 nm, what is the length (in km) of one strand of DNA when it is stretched out to its maximum length (not in a helix)?