Chemistry Answers

If we start with 0.00240 M NOBr, what concentration of NOBr will remain after 5.00 minutes of reaction? The reaction is second order.

A mixture of 0.20 M acetic acid and 0.30 M sodium acetate is give. Calculate the pH of the medium if the pKA of the acetic acid is 4.76

You burn a 15g jellybean to warm 50 mL of water, which increases the temperature of the water 25 °C. How many calories of heat are transferred from the jellybean to the water? Assume there is no heat loss.

A solution is made by dissolving 0.100 mole of NaCl in 8.60 mole of water.

a) What is the mole fraction of the solute?

b) What is the mass percent of the solute?

c) What is the molality of the solute?

A solution of 20.91 % by weight H2SO4 has a specific gravity of 1.150. What is the

normality of this solution? Water is added to dilute this solution to a solution of

3.03% by weight H2SO4 (SG= 1.020). What is the new normality of the resulting

solution and how were they mixed? (Assume 100 mL of the original solution was

used.)

Use the localized electron model to describe the bonding in hydrogenvcyanide and phosgene(COCl2)

For each of the following molecules, write the Lewis structure(s), predict the molecular structure (including bond angles), give expected hybrid orbitals on the central atom, and predict the overall polarity. 

       a. OF2    b. AsF5   c. IF5   

Increasing the temperature increases reaction rate because

A ) the activation energy of the reaction decreases (B)collision frequency increases C) Increases the rate of forward as well as backward reaction equally (Đ) all

2-Which of the following has a maximum wavelength? (A) Far infra-red frequency (B) Gamma rays (C)UV light (D) X-rays