Search our library of Chemistry A Level questions

Top answers

Chemistry

A Level

Chlorine, 15 g, is contained in a vessel with a volume of 0.80 dm3 at 330 K. Calculate the pressure exerted when the chlorine is treated as a perfect (ideal) gas giving your answer in terms of kPa

PV=nRT V=0.8 dm³=0.8 x 10^-3 m³P= nRT/V R= 8.31 J K^-1mol^-1T= 330 K n= mass/mr n = 15 g/ (2x35.5 g mol^-1) n = 0.212 mol P = (0.212 mol x 8....

Answered by Harry G. • Chemistry tutor

2225 Views

ii) The maximum permitted sulfate concentration in water is 250mg dm^-3, 200cm^3 of aqueous BaCl2 is added to 300cm^3 of water at the maximum permitted sulfate level, and a white precipitate formed. Calculate the minimum conc. (mol dm^3)of the BaCl2

250x10^-3= 0.25g dm^-3sulfate mr x moles = mass0.25 x 3/10 = 0.075 g sulfatemr sulfare = 32 + (4 x 16) = 96moles sulfate = 0.075/96 = 7.8125 x10^-4Per equation above: moles SO₄

Answered by Josh M. • Chemistry tutor

1628 Views

When aqueous barium chloride is added to a solution containing sulfate ions a white precipitate is formed. i)Write the ionic equation for the formation of this precipitate.

Ba²⁺_(aq)+SO₄^2-_(aq)---->BaSO_4(s)

Answered by Josh M. • Chemistry tutor

8959 Views

What is bond polarity and why does it exist?

To understand bond polarity, you first must understand electronegativity. Electronegativity is the ability of the nucleus of any atom to attract electrons from another atom, it is dependant on the nuclear...

Answered by Catherine M. • Chemistry tutor

2054 Views

What is fractional distillation used for in industry? Explain the molecular basis behind it.

Separating different sized hydrocarbons (from crude oil)Different length hydrocarbons have different strength VDW forces between their moleculesTherefore longer length hydrocarbons have stronger VDW force...

Answered by Nick G. • Chemistry tutor

1734 Views