Top answers

Molecules of hydrogen chloride, HCl, and molecules of fluorine, F2, contain the same number of electrons. Hydrogen chloride boils at –85 °C and fluorine boils at –188 °C. Explain why there is a difference in the boiling points of HCl and F2.

F2 has temporary dipole-dipole interactions known as van der Waals’ forces. Whilst HCl has permanent dipole-dipole interactions. The intermolecular forces in HCl are stronger than that in F2 (permanent dipol...
FG
Answered by Freddie G. • Chemistry tutor
9014 Views

What is the equilibrium constant?

Imagine a bathtub that someone forgot to plug, but they left the tap open. If the water from the tap is running fast enough, after some time the speed at which water drains and the speed at which water fills...
WL
3166 Views

PharmaPlus, a drug developer, is required by law to carry out clinical trials on the novel drug ‘AccuPreasure’. AccuPreasure is to be marketed for control of high blood pressure. Give three questions that clinical trials are designed to answer.

Is the drug safe for human use? Are there any side-effects? How significant are these? What is the safe-dose? What is the maximum concentration of AccuPressure that will not produce adverse effects? Does Acc...
JM
Answered by Joseph M. • Chemistry tutor
2518 Views

Phosphorus is burned in air at 500 ºC to produce gaseous phosphorus(V) oxide. 220 g of phosphorus was reacted with an excess of air. Calculate the volume, in m3, of gaseous phosphorus(V) oxide produced

Additional information given: P 4 (s) + 5O 2 (g) = P 4 O 10 (g) Pressure = 101kPa Temp = 500 o C gas constant R = 8.31JK -1 mol -1 Question to student: What are the first observations from the equation? Equa...
NB
Answered by Natalie B. • Chemistry tutor
5599 Views

Why does ice float on water? Use the structure of different states of matter to support your answer.

In a liquid, the particles are very close together, but can move around each other. In a solid, the particles are packed together. Depending on the substance, the solid particles can either be very well-orde...
AB
Answered by Akash B. • Chemistry tutor
9608 Views