mistakes in paper 3

Predict the CH2 splitting patterns in the following compounds:

BrCH2CH2Br

BrCH2CH2CH2Br

BrCH2CH2Br: singlet

BrCH2CH2CH2Br: triplet, quintet

mass of grams to milligrams

x1000

mass of four tablets: 2.8g

vol of gas collected at RTP = 48.0 cm3

Student reacts Na2CO3 with the following:
Determine the mass of paracetemol and ibuprofen in one tablet in mg

mass ibuprofen: 206 mg

mass paracetemol: 494 mg

Define the letters and explain

SO3 2- and Cl2 balanced equation

H2O SO3 2- + Cl2 → SO4 2- + 2Cl - + 2H+

Form the ionic equation for SO3 2- and H+ / Cr2O7 2-

3SO₃ ^2- + Cr2O72- + 8H+ → 2Cr 3+ + 3 SO4 2- + 4H2O

what part of a water molecule does the central metal ion connect to and why

The oxygen, because that’s where the dative bond is

Draw the arrows for this mechanism on A and B

Draw a dot and cross diagram for NaBH4

contains Na + ions

and BH4 - ions

Name the following compound: SO3 2-

Sulfate (IV)

The element with the highest first ionisation energy

Helium

Elements which forms a compound with fluorine that has octahedral molecules

Sulfur

Element which has a density of 1.33 × 10-3 g cm-3 at rtp

O

Describe how to filter pure solid (4)

Dissolve impure solid in minimum volume of hot

solvent

 Cool solution and filter solid

 Scratch with glass rod

 Wash with cold solvent/solvent and dry

What technique can be used to find out moles of liquid at equilbrium

Titration

When can you use moles instead of concentration to find out Kc

Same number of moles on each side of the equation so units cancel out

Draw an aldehyde

Draw a similar reaction with propanone

boiling point of NH3 is lower than boiling point of NH4NO3
why (2)

state oxygen states of Ns In NH4NO3 (1)

1. NH4NO3 has ionic bonding, NH3 has intermolecular forces

2. ionic bonds are stronger than / require more energy to break than intermolecular forces

3. In NH3, -3. In NO3-, +5

C8H18 + C2H5OH + 15½ O2 → 10 CO2 + 12 H2O 

M(C8H18) = 114 AND M(C2H5OH) = 46

OR 1 mol C8H18 + 1 mol C2H5OH has mass of 160 g 

50 mol C8H18 OR 50 mol C2H5OH OR 50 mol (C8H18 + C2H5OH) OR 8.00 kg fuel contains 50 mol C8H18 + 50 mol C2H5OH 

Energy = (50 × 5470) + (50 × 1367) OR 50 × (5470 + 1367) OR 50 × 6837 OR 273500 + 68350 = 341850 (kJ) 

5 H2S + 2 MnO4 – + 6 H+ → 2 Mn2+ + 5 S + 8 H2O