CHEMISTRY UNIT 2 FREQUENT TYPE QS

HESS LAW:

Formation formula

products-reactants

If a base is in the conical flask, and acid is being added from the burette, what is the color change in methyl orange and phenophtalein?

Methyl orange- yellow to orange

Phenophtalein- pink to colorless.

Compare and constrast the reactions of sulfuric acid with potassium iodide and potassium chloride.

SIMILARITIES:

1- Both produce steamy fumes.

2- Both produce hydrogen halides.

DIFFERENCES:

(describe what all formed and observations)

KCL is not a redox reaction, H2SO4 acts as an acid here.

KI is a redox reaction.

Iodide ions are a stronger reducing agent than chloride ions (as you go down the group, the reducing agent becomes stronger.)

Why alcohol B is completely soluble in ethanol but only slightly soluble in water?

London forces between B and ethanol, makes it soluble.

Hydrogen bonds between B and water make it less soluble.

Intermolecular forces formed between B and ethanol are stronger.

ADV AND DISADV OF USING HIGH PRESSURE

ADV:

1- high yield, shifts…(depends on question)

DIS ADV:

1-More expensive equipment needed

2- Health and safety risks

3- Requires more energy.

Why when lithium reacts with excess oxygen it only forms lithium oxide and when sodium reacts with excess oxygen it forms sodium oxide and sodium peroxide?

Sodium ion has a larger ionic radius than lithium ion.

How an intermediate J is formed? RX—-> ROH

Heterolytic bond fission occurs

Pair of electrons in C-Br bond are transferred to bromine atom.

How adding more alcohol makes something more viscous?

Forms more hydrogen bonds (depends on how many OH groups are there).

Very strong intermolecular forces.

Test to identify an aqueous solution containing hydrogencarbonate ions, HCO3-

Nitric acid.

What are the reagents that could be used to produce a chloroalkane from a tertiary alcohol?

PCL5, concentrated HCL, concentrated H2SO4 and KCL.

Reagents for testing for carboxylic acid

Add aqueous sodium carbonate.

Effeservence shows the presence of CO2 gas.

Reagents and conditions for alkene to alcohol

Reagents and conditions for alkene to diol

ALKENE TO ALCOHOL

1- Concentrated phosphoric acid

ALKENE TO DIOL

1- Potassium permanganate in dilute sulfuric acid.

Adv of using solar power over methane gas.

ADV:

Solar power is a renewable source and hence does not produce greenhouse gases.

Sustainable.

DIS ADV:

It is expensive

Takes up land space.

Urea and ammonium nitrate are both soluble in water, describe the differences in the interactions of water molecules with both urea and ammonium nitrate.

Hydrogen bonds formed between water and urea.

Urea is soluble in water as the hydrogen bonds formed are stronger.

Ammonium nitrate is soluble in water as water hydrates the ions.

If a gas is cooled, what happens to the area under the curve and the position of the peak of a boltzaan graph?

area under the graph DECREASES

position of peak SHIFTS TO THE LEFT

ADV of carrying all reaction on same site.

Low energy costs.

Less land needed.

Prevents more chemical waste through transfer losses.

If the calorimetric value was included in the calculation, what would happen to the enthalpy change value?

The heat energy would be greater and hence the enthalpy value would increase as well, more exothermic.

Production of carbon dioxide reaction.

CO32- (s) + 2H+ (aq) —> CO2 (g) + H2O (l)

How would the mean titre value change if the hyroxide used is more soluble?

The mean titre value would be greater.

Priority of highest boiling temperature.

MORE ELCTRONS>HYDROGEN BONDING> BRANCHED AND MORE ELECTRONS.

Appropriate number of significant figures

3 S.F!!!!!!

Rate of reaction linked to?

Nucleophile attack linked to?

C-X BOND ENTHALPY/BOND STRENGTH

BOND POLARITY

What is the role of sulfuric acid when it reacts with sodium iodide?

OXIDISING AGENT

Role of hydroxide ion with C-CL halogenoalkane

Role of hydroxide ion with C-I halogenoalkane

BASE

NUCLEOPHILE