Past papers

Can bromine displace bromine

No

What color is silver iodide precipitate?

Yellow

Slower rate of reaction

C-Br bond stronger than C-I bond

Line for bromoutane below iodophor butane

Why would you not use water for step 1?

It would form an alcohol

A

Use limiting reagent

Are these values for formation or normal or bond enthalpy

And why

Formation

1 mole of substance is formed

Not combustion as not burned in oxygen

How do you find the number of molecules here

3.0111×10²4

Divided by 6 as 6 carbon atoms in cyclohexane

Divide by avogadros

Multiply by mr

Moles formula

Number of particles divided by avogadros

Explain why the C-Cl bond is polar

Chlorine is more electronegative than carbon

So chlorine becomes slightly negative and carbon becomes slightly positive

There are van der waa;s forces between non polar molecules

Explain what causes these forces

Random movement of electrons in one molecule

Induces a dipole in another

Dipoles in different molecules attract

State how the detector enable the relative abundance of each ion to be determined

Abundance is proportional to size of current

Trigonal pyramidal bond angle

107

Test for ammonium nitrate

Add NaOH

Hold damp red litmus paper at mouth of tube

turns blu

What is the observation for magnesium nitrate with sodium hydroxide

White precipitate

Standard enthalpy of formation definition

Enthalpy change when 1 mole of a substance is formed from its elements a

All substances in their standard states

Formula for percentage atom economy

Mr of Desired product

Divided by

Mr of total reactant

AlLWAYS REACTANT

D

B is ionic bond in and A and C have a full outer shell now

Is hydrogen a non metal

Yes

C

Describe trend in first ionisation energy inperiod 3

Increases

Atomic radius in period 3 describe the trend

Decreases

C

Look for finger print region and look for match to known spectrum

Absorbs infrared radiation

Absorbs around 3000 and 1200 cm-1

ABSORBs UV radiation

Orange to green