At 230 ºC, K_c = 0.093 for the equilibrium 2NO (g) + O₂ (g) ⇌ 2NO₂ (g), calculate the concentration of O₂ in an equilibrium mixture containing 0.542 mol dm^-3 of NO and 0.059 mol dm^-3 of NO₂.

After a system has reached equilibrium, as shown by the dotted line, the rate of forward and the reverse reaction are equal rate. Which of the dotted-lines in the disgram represents it?

A high E_a means that relatively few __________ have the required energy to produce the __________ complex.

You are given the covalent molecules:

Select the molecule(s) that surround the 6 electrons in the central atom.

The energy from burning 0.05g of propane was transferred to 10 cm³ of water to raise its temperature by 10 °C. What is the enthalpy change? (Assume that 1cm³ of water has a mass of 1g, the specific capacity of water is 4.18 J g^-1 °C^-1.)

When ammonium chloride is dissolved in water, the flask become quite cold to touch. Why?

 Which of the following atoms or ions has the electronic configuration 1s²2s²2p⁶3s²3p⁶?

The general formula of ethyl methyl ethers is __________.

Heteronuclear diatomic molecules which have __________ are __________.