Enthalpy

The bombardier beetle uses an explosive discharge as a defensive measure. The chemical reaction involved is the oxidation of hydroquinone by hydrogen peroxide to produce quinone and water. Please see the attached file for full problem description.

Calorimetry

In a coffee-cup calorimeter, 1.10 g of NH4NO3 is mixed with 76.0 g of water at an initial temperature of 25.00°C. After dissolution of the salt, the final temperature of the calorimeter contents is 23.93°C. Assuming the solution has a heat capacity of 4.18 J/°C · g and assuming no heat loss to the calorimeter, calculate the ...continues

Hess's Law

see attachment

soluability and Ksp

A saturated solution of silver chloride, AgCl contains 1.92 mg of AgCl per liter of solution. What is the value of the soluability product constant Ksp for silver chloride. I know that soluability for AgCl at 25 degrees celcius ksp = 1.8 x 10 -10, however I am not sure if I would even need to incorporate this into the equati ...continues

solving for pH

I have .20M of a solution NaCN. Ka for HCN = 4.0 x10 10. How do I solve for pH?

molarity and equilibrium

A sodium hydroxide solution was standardized by weighing 2.425 g of oxalic acid, H2C2O4*2H2o and diluting it to 250 mL in a volumetric flask. Then 25.0 mL of this acid solution was titrated with 30.20 mL of base. Based on this information, how do I calculate the molarity of the sodium hydroxide solution?

Wavelength

Suppose you are standing 225 m from a radio transmitter. What is your distance from the transmitter in terms of the number of wavelengths if a) The station is broadcasting at 1150kHz (on the Am radio band) (1 kHz=1 x 10^3(to the third power), or 1000 cycles per second) Distance from transmitter:___________________wavele ...continues

Wavelength

Violet light has a wavelength of about 410 nm. What is its frequency? Calculate the energy of one photon of violet light. What is the energy of 1.0 mol of violet light photons? Compare the energy of photons of violet light with those of red light. Which is more energetic and by what factor? Frequency of violet light:____ ...continues

Wavelength

If OTA 104289 is available please assist. If not, please list step by step. Thank You. A beam of electrons (m=9.11 x 10 (-31) negative thirty first power has an average speed of 1.3 x 10^8 (eigth power) m*s (-1) s to to the negative first power. What is the wavelength of electrons having this average speed? ^=__________ ...continues

Notations

If OTA 104289 is available, please assist. Compare the elements B, Al, C, and Si. a)Which has the most metallic character? b)Which has the largest atomic radius? c) Which has the most negative electron affinity? d) Place the three elements B, Al, and C in order of increasing first ionization energy. ________ _ ...continues