Chemistry Random Retrieval Y12

How many functional group isomers of C₃H₆O₂ are there?

It's really difficult to get all of these structures, so don't panic if you miss some. Just spend some time sketching out all the possibilities and remembering some simple rules, e.g carbon forms 4 bonds, oxygen forms 2 etc. Be creative!

Choose one of the following options:

Choose one of the following options:

What is the oxidation number of BROMINE in

BrO^-

Which of these ions has the greatest polarising power?

Calculate the value of the standard enthalpy change of formation of methane given that the values for standard enthalpy changes of combustion are -890 kJ mol^-1 for methane, -393 kJ mol^-1 for carbon and -286 kJ mol^-1 for hydrogen gas.

Which of these statements are true for the hydrides of group 5: NH₃, PH₃, AsH₃ and SbH₃:

(i) the molecules decrease in size down the group

(ii) the boiling point of ammonia is higher than expected from the general trend in values down the group

(iii) none of the molecules is polar

(iv) only ammonia is affected by hydrogen bonding

What is the concentration of hydroxide ions in a 0.050 mol dm^-3 solution of barium hydroxide?

What is the concentration of a solution of sodium hydroxide that is made by dissolving 20.0g of the solid in water and making the solution up to 250 cm³? (Relative atomic masses: Na = 23, O = 16, H = 1)

Which of these conversions are reductions?

(i) CrO₄^2- to Cr₂O₇^2-

(ii) CrO₄^2- to Cr³⁺

(iii) CrO₄^2- to CrO₃

(iv) CrO₃ to Cr₂O₃

What is the concentration of a solution of sodium hydroxide that is made by dissolving 20.0g of the solid in water and making the solution up to 250 cm³? (Relative atomic masses: Na = 23, O = 16, H = 1)

What is the volume of 0.020 mol oxygen at 27^oC and 100 kPa pressure given that the value of the gas constant R = 8.31 J mol^-1K^-1?

Which of these compounds has a relatively low melting point (below 500 ^oC)?

In which of these molecules do the intermolecular forces arise largely from attractions between permanent dipoles?

What is/are the bond angle(s) found in PCl₅?

(i) 90^o

(ii) 104.5^o

(iii) 120^o

(iv) 180^o

What is the bond angle found in BeCl₂?

How many moles of molecules are there in 0.240 g bromine?

What is the electronic configuration of bromine? Enter your answer in the following format 1s2 2s2 etc. (note the space between each sub-shell!) Follow the aufbau order of sub-shell filling.

What is the electronic configuration of carbon?

Enter your answer in the following format 1s2 2s2 etc. (note the space between each sub-shell!) Follow the aufbau order of sub-shell filling.

Each of these statements is true. From which statement is it possible to predict, by application of Le Chatelier's principle that the solubility of sodium hydroxide increases with temperature?

Which of these systems is NOT in a state of dynamic equilibrium?

The standard enthalpy change of formation of N₂O_(g) is +82 kJ mol^-1. This shows that

The energy needed to atomise 1 mol of gaseous ethene, C₂H₄ is 2087 kJ mol^-1. Calculate the average bond enthalpy for a C-H bond given that the bond enthalpy for the C=C bond is +347 kJ mol^-1.

When chlorine reacts with cold, aqueous sodium hydroxide the ions formed are:

What is the oxidation number of CARBON in

CCl₄

What is the oxidation number of CHROMIUM in

Cr₂O₇^2-

What is the oxidation number of BROMINE in

BrO^-

What is the oxidation number of CHLORINE in

ClO₂

Across period 3 from sodium to argon:

(i) the metal with the lowest melting point is sodium

(ii) the element with the highest melting point is silicon

(iii) the non-metal with the lowest melting point is argon

(iv) the melting points of all the non-metals are lower than those of the metals

Which of the following statements describe molecules that are stereo isomers?

(i) molecules whose atoms have a different arrangement in space

(ii) molecules that have the same molecular formula

(iii) molecules in which the atoms are joined to the same neighouring atoms

(iv) molecules which the same atoms but the atoms are bonded in a different order

How many structural isomers of C₄H₈O are there?

It's really difficult to get all of these structures, so don't panic if you miss some. Just spend some time sketching out all the possibilities and remembering some simple rules, e.g carbon forms 4 bonds, oxygen forms 2 etc. Be creative!

How many structural isomers of C₆H₁₄ are there?

A compound X with the molecular formula C₄H₁₀O has a broad peak in its IR spectrum at 3500cm^-1.

Oxidation of X with excess potassium dichromate(VI) gives a product Y which is not an acid and does not reduce Fehling's solution.

Y has a strong peak in its IR spectrum at 1700cm^-1.

Identify X and Y. (See also the data in question 9.)

There are two main peaks in the infra-red spectrum of carbon dioxide.

This shows that carbon dioxide molecules:

Which reagent can be used to convert butan-1-ol to but-1-ene?

What type of reaction takes place on passing the vapour of ethanol over hot aluminium oxide? (Water and an alkene are produced)

What is the H-C-H bond angle in ethene?

A 5.6 g sample of a pure alkene with one double bond in its molecules, reacts with 16.0 g bromine. What is the formula of the alkene? (Relative atomic masses: C = 12, H = 1, Br = 80)

[1] C₂H₄

[2] C₄H₈

[3] C₆H₁₂

[4] C₈H₁₆

Which of these hydrocarbons is an alkane?