Question 1 A substance was analysed and was found to have a boiling point of 450 °C.
At room temperature it is a soft grey solid.
Which temperature could be the melting point of a pure sample of the substance?
A. -12 °C
B. 56 °C to 72 °C
C. 250 °C to 275 °C
D. 142 °C
[1 mark]

Consider the reaction: n2(g) + o2(g) ? 2no(g) kc = 0.10 at 2000oc starting with initial concentrations of 0.040 mol/l of n2 and 0.040 mol/l of o2, calculate the equilibrium concentration of no in mol/l how would this be done?

How many molecules are found in 1.32 mol of nacl?

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.