Chemistry Answers

Calculate the ΔH of the following problems.

1. How many joules are required to raise the temperature of 450 mL of water from 30°C to 100°C?

2. The specific heat of copper metal is 0.385 J/g-°K. How many kJ of heat are needed to raise the temperature of 1.1 kg block of copper from 27.5°C to 50°C?

Suggest reasons why a glass electrode can be used for the determination of the pH of an aqueous solution

Find the partial pressure of carbon dioxide in a gas mixture with a total pressure

of 30.4 kPa if the partial pressures of the other two gases in the mixture are 16.5

kPa and 3.7 kPa.

Use the localised electron model to describe the bonding in hydrogen cyanide and phosgene(cocl2)

a sample of air, upon analysis by an environmentalist showed that it contains 1.4x 10 of mercury per 50 ml of solution, what is the mercury concentration in a ppm chemistry answer

The decomposition of PCl5 is shown below:

PCl5(g)⇌PCl(g) + Cl(2)

Kc 3 = 0.029 at 85°C

Find out if the reaction proceeds forward, backward, or if the system is at equilibrium when a 1 liter

container is filled with 0.4 mole PCl5, 0.5 mole PCl3, and 0.2 mole Cl2.

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?