Category: Chemistry

3.94g of potassium hydrogencarbonate was dissolved in deionised water and made up to 100cm³ in a volumetric flask.

10.0cm³ samples were titrated against sulfuric acid solution of concentraion 0.150 mol dm^-3.

A mean titre of 11.70cm³ of sulfuric acid solution was obtained.

Calculate the percentage purity, by mass, of the original solid. (Don't include the % symbol and give answer to 1 decimal place!)

2.79g of sodium carbonate was dissolved in deionised water and made up to 250cm³ in a volumetric flask.

20.0cm³ samples were titrated against hydrochloric acid solution of concentraion 0.350 mol dm^-3.

A mean titre of 11.80cm³ of hydrochloric acid solution was obtained.

Calculate the percentage purity, by mass, of the original solid. (Don't include the % symbol and give answer to 1 decimal place!)

0.925g of lithium hydroxide was dissolved in deionised water and made up to 250cm³ in a volumetric flask.

25.0cm³ samples were titrated against sulfuric acid solution of concentraion 0.100 mol dm^-3.

A mean titre of 13.75cm³ of sulfuric acid solution was obtained.

Calculate the percentage purity, by mass, of the original solid. (Don't include the % symbol and give answer to 1 decimal place!)

1.66g of potassium hydroxide was dissolved in deionised water and made up to 100cm³ in a volumetric flask.

25.0cm³ samples were titrated against nitric acid solution of concentraion 0.300 mol dm^-3.

A mean titre of 23.45cm³ of nitric acid solution was obtained.

Calculate the percentage purity, by mass, of the original solid. (Don't include the % symbol and give answer to 1 decimal place!)

2.5g of potassium hydroxide was dissolved in deionised water and made up to 250cm³ in a volumetric flask.

25.0cm³ samples were titrated against nitric acid solution of concentraion 0.150 mol dm^-3.

A mean titre of 18.15cm³ of nitric acid solution was obtained.

Calculate the percentage purity, by mass, of the original solid. (Don't include the % symbol and give answer to 1 decimal place!)

Calculate the pH of a solution created by the addition of 30.0cm³ 0.100 mol dm^-3 lithium hydroxide solution to 35.0 cm³ 0.100 mol dm^-3 hydrobromic acid solution.

Remember to give your answer to 3 sig.fig.

By titration, it was found that an average titre of 9.90cm³ of 1.00 mol dm^-3 solution of potassium carbonate was required to just neutralise a 25.00 cm³ sample of sulfuric acid solution. Calculate the concentraion of the sulfuric acid solution.

The equation for the reaction is

K₂CO_3(aq)+H₂SO_4(aq)=>K₂SO_4(aq)+H₂O_(aq)+CO_2(g)

By titration, it was found that an average titre of 21.25cm³ of 2.450 mol dm^-3 solution of sulfuric acid was required to just neutralise a 10.00 cm³ sample of barium hydroxide solution. Calculate the concentraion of the barium hydroxide solution.

The equation for the reaction is

H₂SO_4(aq)+Ba(OH)_2(aq)=>BaSO_4(aq)+2H₂O_(aq)

By titration, it was found that an average titre of 21.30cm³ of 0.100 mol dm^-3 solution of sulfuric acid was required to just neutralise a 25.00 cm³ sample of potassium hydroxide solution. Calculate the concentraion of the potassium hydroxide solution.

The equation for the reaction is

2KOH_(aq)+H₂SO_4(aq)=>K₂SO_4(aq)+H₂O_(aq)

By titration, it was found that an average titre of 22.85cm³ of 0.300 mol dm^-3 solution of nitric acid was required to just neutralise a 25.00 cm³ sample of sodium carbonate solution. Calculate the concentraion of the sodium carbonate solution.

The equation for the reaction is

2HNO_3(aq)+Na₂CO_3(aq)=>2NaNO_3(aq)+H₂O_(aq)+CO_2(g)

What volume (in cm³) of deionised water would you need to add to 50.0cm³ of ammonia solution to dilute it from a concentration of 10.0 mol dm^-3 into a concentration of 1.00 mol dm^-3?

What volume (in cm³) of deionised water would you need to add to 100cm³ of hydrochloric acid to dilute it from a concentration of 2.00 mol dm^-3 into a concentration of 1.00 mol dm^-3?

Calculate the concentration of iodine in a solution of volume 4.80dm³ that contains 250 g of iodine

I=126.9

Calculate the concentration of potassium hydrogencarbonate in a solution of volume 280cm³ that contains 50.0 g of potassium hydrogencarbonate

K=39.1 H=1.0 C=12.0 O=16.0

Calculate the concentration of potassium hydrogencarbonate in a solution of volume 900cm³ that contains 50.0 g of potassium hydrogencarbonate

K=39.1 H=1.0 C=12.0 O=16.0

Calculate the volume of solution in cm³ that would contain 0.200 mol of lithium iodide if the concentration of the solution is 0.800 mol cm^-3

Calculate the volume of solution in dm³ that would contain 0.400 mol of copper (II) sulfate if the concentration of the solution is 1.10 mol dm^-3

Calculate the volume of solution in dm³ that would contain 0.800 mol of sulfuric acid if the concentration of the solution is 0.200 mol dm^-3

Calculate the volume of solution in cm³ that would contain 0.150 mol of chlorate (I) ions if the concentration of the solution is 0.150 mol cm^-3

Calculate the number of moles of hydrofluoric acid in a solution of volume 22.45 cm³ and a concentration of 0.250 mol dm^-3

Calculate the volume of gas (in dm³) of 1.40 mol of sulfur hexafluoride if the gas is at a temperature of 3000K and a pressure of 1000kPa

Calculate the volume of gas (in m³) of 0.500 mol of hydrogen if the gas is at a temperature of 373K and a pressure of 5000Pa

Calculate the volume of gas (in dm³) of 2.00 mol of gaseous ammonia if the gas is at a temperature of 1000K and a pressure of 75000Pa

Calculate the volume of gas (in cm³) of 0.0500 mol of neon if the gas is at a temperature of 273K and a pressure of 505000Pa

Calculate the volume of gas (in dm³) of 0.400 mol of helium if the gas is at a temperature of 273K and a pressure of 50000Pa

Calculate the temperature of a sample of butane (in ^oC) if 0.110 mol of butane has a volume of 879cm³ and is at a pressure of 700kPa

Calculate the temperature of a sample of nitrogen (in ^oC) if 0.160 mol of nitrogen has a volume of 1850cm³ and is at a pressure of 120000Pa

Calculate the temperature of a sample of fluorine (in ^oC) if 0.890 mol of fluorine has a volume of 125dm³ and is at a pressure of 95000Pa

Calculate the temperature of a sample of neon (in K) if 2.00 mol of neon has a volume of 24.00dm³ and is at a pressure of 50000Pa

Calculate the number of moles of gas present at r.t.p in 6000 cm³ of methane.

Calculate the number of moles of magnesium hydroxide if you have 62.0 g of magnesium hydroxide

H=1.0 C=12.0 O=16.0

Calculate the number of moles of fluorine if you have 76.0 g of fluorine

F=19.0

Calculate the number of moles of glucose if you have 36.0 g of glucose

H=1.00 C=12.0 O=16.0

Calculate the number of moles of FeSO₄ . 7H₂O if you have 45.6 g of FeSO₄ . 7H₂O

S=32.1 Fe=55.8 O=16.0 H=1.0

Calculate the number of moles of N₂ if you have 28.0 g of N₂

N=14.0

Calculate the number of moles of Al₂(SO₄)₃ if you have 17.1 g of Al₂(SO₄)₃

S=32.1 Al=27.0 O=16.0

Calculate the number of moles of H₂SO₄ if you have 27.0 g of H₂SO₄

S=32.1 H=1.0 O=16.0

Calculate the mass of iodine that you would have if you had 0.0500 mol of iodine

I=126.9

Calculate the mass of fluorine that you would have if you had 1.75 mol of fluorine

F=19.0

Calculate the mass of P₂O₅ that you would have if you had 0.100 mol of P₂O₅

P=31.0 O=16.0

Barium hydroxide solution will neutralise hydrochloric acid according to the equation

Ba(OH)₂+2HCl =>BaCl₂+2H₂O

What volume of 0.1mol dm^-3 HCl will neutralise 250 cm³ of 0.2mol dm^-3 Ba(OH)₂?

Which solution of NaCl is the most concentrated?

How many moles of molecules are present in 48.0 dm³ of butane? (all volumes measured at r.t.p.)

KClO₃ => KClO₄ + KCl

The empirical formula of a compound:

Work out the names of each of the following compounds from their formula. Use the data sheet Names & Formulae of Some Common Ions

Formulae are Case Sensitive.

Remember to use regular numbers in formulae e.g. H2O not H₂O

HBr

silicon (IV) fluoride

sulfur (VI) fluoride

iron (III) sulfate

Calculate the relative molecular mass (formula mass) of zinc hydroxide, Zn(OH)₂

What is the organic product when benzene reacts with ethanoyl chloride in the presence of aluminium chloride?

Which types of change are involved in this sequence of reactions, though not necessarily in the order listed?

CH₃CO-C₆H₅ -> CH₃CO-C₆H₄-NO₂ -> CH₃CHOH-C₆H₄-NO₂ -> CH₃CH(OCOCH₃)-C₆H₄-NO₂

(i) esterification

(ii) reduction

(iii) nitration

(iv) hydrolysis

In a peptide made up of a sequence of four amino acids the number of peptide bonds is:

When 0.08 g magnesium ribbon reacts with 50 cm³ of 2.00 mol dm^-3 hydrochloric acid the reaction produces 80 cm³ gas in 400 seconds at room temperature and pressure but then stops. On repeating the reaction under the same conditions with 0.08 g magnesium ribbon and 100 cm³ of 1.00 mol dm^-3 hydrochloric acid the outcome is that the reaction:

What are the units of k for this reaction?

[1] s^-1

[2] mol^-1 dm³ s^-1

[3] mol^-2 dm⁶ s^-1

[4] mol^-3 dm⁹ s^-1

Which graph represents the disappearance of a reactant that displays first order kinetics?

K_p = 4 atm for the dissociation of N₂O₄ at 350 K when the equilibrium is described by this equation.

N₂O_4(g) <=> 2NO_2(g)

What is the value of K_p for this equilibrium:

2NO_2(g) <=> N₂O_4(g)?

Consider the following equilibrium for the reaction that generates hydrogen for use in the Haber-Bosch Process:

CH_4(g) + H₂O_(g) <=>CO_(g) + 3H_2(g)

100 mol of CH₄ was mixed with 100 mol of H₂O and 200 mol of H₂.The mixture was given time to reach equilibrium. At this point, 350 mol of H₂ was present in the mixture. The pressure inside the 1.20 m³ vessel was measured as 400 kPa

Calculate the value of K_p (in units: kPa²) under these conditions.

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (‘A Selection of Standard Electrode Potentials’can be found in TOOLS>Data Sheets)

Is Cu²⁺_(aq) capable of oxidising Ag_(s)?

Consider a cell constructed from the following half-cells:

Zn²⁺_(aq) + 2e^- <=> Zn_(s) E^ϴ/V = -0.76

Cu²⁺_(aq) + 2e^- <=>Cu_(s) E^ϴ/V = +0.34

Which half-cell will form the cathode in this cell? Think very carefully about the definition of a cathode!

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (‘A Selection of Standard Electrode Potentials’can be found in TOOLS>Data Sheets)

Which chemical species is most resistant to oxidation?

Consider a cell constructed from the following half-cells:

Mg²⁺_(aq) + 2e^- <=> Mg_(s) E^ϴcell/V = -2.37

Ag⁺_(aq) + e^- <=> Ag_(s) E^ϴcell/V = +0.80

If the solution of Mg²⁺_(aq) was 2.00 mol dm^-3, would you expect to see a greater or smaller value of E^ϴcell/V than you would if the cell was set-up under standard conditions?

Work out the ratio of the species in the following half-equation.

Cu => Cu²⁺ + e^-

Using oxidation numbers (states) work out the ratio of the species in the following half-equation.

S₂O₃^2- + H₂O => SO₄^2- + H⁺ + e^-

Using oxidation numbers (states) work out the ratio of the species in the following half-equation.

I₂ + e^- => I^-

Which of these complex ions acts as an acid in aqueous solution?

(i) [Ni(NH₃)₆]²⁺

(ii) [Al(H₂O)₂(OH)₄]^-

(iii) [Ag(NH₃)₂]⁺

(iv) [Cr(H₂O)₆]3⁺

Which types of chemical bonding feature in crystals of the compound K₂[Ni(CN)₄]?

(i) ionic bonding

(ii) covalent bonding

(iii) dative covalent bonding

(iv) metallic bonding

For the following equilibrium K_c = 25.0 mol^-2 dm⁶ at a particular temperature.

CO_(g) + 2H_2(g) <=> CH₃OH_(g)

Which of these changes of conditions alter the value of K_c?

(i)Raising the concentration of hydrogen

(ii)Adding a catalyst

(iii)Raising the pressure

(iv)Lowering the temperature

Consider the following reaction:

2NO_2(g) + F_2(g) => 2NO₂F_(g)

The rate equation was found, by experiment:

rate = k [NO₂] [F₂]

Which of the following statements is/are true?

(i) The mechanism has more than one step

(ii) Doubling [NO₂] doubles the rate of the reaction

(iii) NO₂ is produced in one of the steps

(iv) The mechanism has only one step

The activation energy for the reaction of cobalt metal with aqueous S₂O₈^2- ions is close to 50 kJ mol^-1. The rate of reaction for the metal when a cylinder of cobalt metal rotates rapidly in a solution of aqueous S₂O₈^2- ions at 15^oC is 1.80 mg min^-1. This suggests that at 25^oC the rate of reaction would be about:

Which of these compounds are chiral?

(i) propan-1-ol,

(ii) propan-2-ol,

(iii) butan-1-ol,

(iv) butan-2-ol

Which of these compounds are chiral?

(i) CH₂Cl₂

(ii) CH₂ClBr

(iii)CHCl₂F

(iv) CH₃CHClBr

Which of these compounds are functional group isomers of

HCO₂CH₂CH₂CH₃?

(i) ethyl ethanoate,

(ii) 2-methylpropanoic acid,

(iii) methyl propanoate,

(iv) butanoic acid

The rate equation for the reaction of hydroxide ions with 2-bromo-2-methylpropane takes the form:

rate = k[C₄H₉Br].

This indicates that:

(i) the rate determining step involves hydroxide ions

(ii) doubling the concentration of the halogenoalkane doubles the rate of reaction

(iii) the reaction takes place in one step

(iv) the reaction takes place by the S_N1 mechanism (a 2 step mechanism)

The reaction of benzene with ethanoyl chloride in the presence of aluminium chloride

(i) involves CH₃-CO⁺ as an intermediate

(ii) forms C₆H₅-CO-CH₃

(iii) is a substitution reaction

(iv) involves nucleophilic attack on benzene

Which statement helps to explain why propene react with hydrogen bromide to form mainly 2-bromopropane and much less 1-bromopropane?

Which of these chemical species are nucleophiles with react with halogenoalkanes?

(i) cyanide ions

(ii) hydroxide ions

(iii) ammonia molecules

(iv) ammonium ions

In which of these reactions between pairs of reagents is the bond breaking homolytic?

(i) butan-1-ol with sodium bromide and concentrated sulfuric acid

(ii) catalytic cracking of hydrocarbons

(iii) bromine with ethene

(iv) bromine with hexane

If the paracetamol molecule shown below is hydrolysed in hot dilute hydrochloric acid, what are the main organic products?

Which types of change are involved in this sequence of reactions, though not necessarily in the order listed?

CH₃CO-C₆H₅ -> CH₃CO-C₆H₄-NO₂ -> CH₃CHOH-C₆H₄-NO₂ -> CH₃CH(OCOCH₃)-C₆H₄-NO₂

(i) esterification

(ii) reduction

(iii) nitration

(iv) hydrolysis

The peak with the largest mass to charge ratio in the mass spectrum of an alkane is detected at mass-to-charge ratio = 58.

This shows that the hydrocarbon:

Choose one of the following options:

The reaction of calcium with water produces:

Using enthalpies of formation Δ_fH, calculate the enthalpy change for the following hydration process.

Na₂S₂O_3(s) + 5H₂O_(l) => Na₂S₂O₃•5H₂O_(s)

Select the data from the 'Selection of Enthalpies of Formation and Combustion' shown above.

If this question was generated from Random Retrieval, this data can also be found in TOOLS>Data Sheets.

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?

A small crystal of iodine is dissolved in hexane to give a violet coloured solution. After adding an equal volume of colourless, aqueous potassium iodide and shaking, the system reaches equilibrium with the hexane layer floating on top of the aqueous layer. At equilibrium:

(i) the concentrations of iodine in the two layers are the same

(ii) the iodine in the hexane turns brown

(iii) the iodine molecules stop moving between the two layers

(iv) the concentrations in each layer stop changing

What is the electronic configuration of scandium? 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.

Calculate the volume of oxygen gas formed on strongly heating 3.40 g sodium nitrate which decomposes according to this equation:

2NaNO_3(s) -> 2NaNO_2(s) + O_2(g)

Assume that the volume of 1 mol of any gas is 24 000 cm³ under the conditions of the experiment.

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

Hydrogen is oxidised when it reacts with:

(i) oxygen to form water

(ii) nitrogen to form ammonia

(iii) chlorine to form hydrogen chloride

(iv) sodium to form sodium hydride

Hydrogen is oxidised when it reacts with:

(i) oxygen to form water

(ii) nitrogen to form ammonia

(iii) chlorine to form hydrogen chloride

(iv) sodium to form sodium hydride

The oxidation number of sulfur in sulfuric acid, H₂SO₄, is:

In a titration, 25 cm³ of 0.100 mol dm^-3 potassium hydroxide was neutralised by 12.5 cm³ dilute nitric acid. What was the concentration of the nitric acid?

Which of these elements has a relatively low boiling point (below 500 ^oC)?

In a close-packed metal structure:

(i) there are no spaces between the atoms

(ii) the atoms are arranged in layers

(iii) the crystal breaks if the layers slide past each other

(iv) each atom touches 12 nearest neighbours.

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

Using the basic rules of VSEPR, what would you expect the bond angle to be in H₂S?

Which of these molecules are overall polar?

(i) CH₃Cl

(ii) CH₂Cl₂

(iii) CHCl₃

(iv) CCl₄

In the formula of water, H-O-H, the lines represent:

(i) shared pairs of electrons

(ii) dative bonds

(iii) covalent bonds

(iv) hydrogen bonds

How many chloride ions touch each sodium ion in the crystal structure of sodium chloride?

This is the equilibrium in a solution of bromine in water:

Br_2(aq) + H₂O(l) <=> HOBr_(aq) + H⁺_(aq) + Br^-_(aq)

The orange colour of bromine disappears on adding

(i) sodium bromide

(ii) water

(iii) dilute hydrochloric acid

(iv) sodium hydroxide solution

The total O.N. of all the halogen atoms in these compounds ClO^-, BrO^-, ICl, XeF₄ is:

Chlorine disproportionates when it reacts with:

The carbonates of group 2 metals (M):

(i) have the formula of the form MCO₃

(ii) are insoluble in water

(iii) become more difficult to decompose on heating down the group

(iv) decompose on heating to the metal and carbon dioxide

What is the oxidation number of CARBON in

CCl₄

What is the oxidation number of MANGANESE in

MnO₄^-

What is the oxidation number of OSMIUM in

OsO₄

What is the oxidation number of CARBON in

CH₄

Which of these statements about atomic and ionic radii are true?

(i) Atomic radii increase down group 2

(ii) Ionic radii increase down group 7

(iii) Atomic radii decrease across period 3

(iv) In period 3 the ionic radii are smaller than the atomic radii

An element which is a solid at room temperature consisting of molecules is:

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!

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.)

This procedure produces a white precipitate which dissolves easily in dilute ammonia solution: heating C₄H₉X for a few minutes with aqueous alkali, then acidifying the mixture with dilute nitric acid and adding silver nitrate. This shows that X is:

What are the conditions for converting 1,2-dichlorethane into ethane-1,2-diol?

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

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

What is the name for this structure:

CH₃CH(CH₃)CH(CH₃)CH₂CH₃?

Which of these hydrocarbons is an alkane?

Which of these alkenes will produce the largest %yield of 2-bromopentane when it is reacted with hydrogen bromide?

Which of these alcohols is a tertiary alcohol?

(i) CH₃CH₂CHOHCH₃

(ii) CH₃CH(CH₃)CHOHCH₃

(iii) CH₃C(CH₃)₂CH₂CHOHCH₃

(iv) (CH₃)₃COH

Choose one of the following options:

A white crystalline solid gives a pale green colour in a flame. Adding silver nitrate to an acidified solution of the solid produces a white precipitate. The solid is:

Chlorine disproportionates when it reacts with:

How many electrons are there in an oxide ion?

How many sulfate ions are there in 0.01 mol aluminium sulfate?

(The Avogadro constant = 6.02 x 10²³ mol^-1)

How many shared pairs of electrons are there in an ethene molecule, C₂H₄?

What is the bond angle found in water?

In the family of hydrocarbons called alkanes:

(i) the boiling points of the straight chain compounds rise as the number of carbon atoms increases

(ii) the intermolecular forces arise from attractions between temporary dipoles

(iii) in any pair of isomers the compound with the more highly branched molecules has the lower boiling point

(iv) the unbranched compounds are all liquids at room temperature.

The main forces which hold a coiled protein chain into an alpha-helix are:

Which of these phrases describes the tertiary structure of a protein?

Which of these characteristics of polymers accounts for the difference between low density and high density poly(ethene)?

[1] the average length of the polymer chains

[2] the type of intermolecular (interchain) forces

[3] the number and size of bulky side groups

[4] the extent of chain branching

Step 5:

How many peaks would you expect to see in the ¹³C spectrym of 3-propyl aminobenzene?

What enthalpy change is represented by the following equation?

2Na_(s) + ½ O_2(g)=> Na₂O_(s)

From your calculation of ΔG in question 8, decide whether the reaction between high pressure steam and methane will be feasible at 1500^oC.

If this question is from a Random Retrieval, you can also carry out this calculation of Gibbs Energy change, ΔG by first working out values for ΔS^Ɵ and ΔH^Ɵ by selecting the appropriate data from the ‘Selection of Thermodynamic Data’ in TOOLS.

Which first-row d-block element forms an oxide used as the catalyst in the synthesis of sulfur trioxide from sulfur dioxide and oxygen?

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (‘A Selection of Standard Electrode Potentials’can be found in TOOLS>Data Sheets)

Which chemical species is most resistant to reduction?

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (‘A Selection of Standard Electrode Potentials’can be found in TOOLS>Data Sheets)?

Can MnO₄^-_(aq) oxidise water into H₂O_2(aq) in acidic condition?

What volume of 0.10 mol dm^-3 hydrochloric acid is needed to neutralise 20.0 cm³ of 0.05 mol dm^-3 barium hydroxide?

Which of these compounds consists of a giant structure of ions?

Which of the following is not a typical property of most metals:

Which of these true statements can help to explain why magnesium has a higher melting point than sodium:

(i) magnesium atoms/ions are smaller than sodium atoms/ions

(ii) the metallic bonds are stronger in magnesium than in sodium

(iii) a magnesium atoms contributes two bonding electrons not one

(iv) the first ionisation energy is higher for magnesium than for sodium.

In which of these solids are there two types of bonding: one strong and one weak?

(i) diamond

(ii) ice

(iii) sodium chloride

(iv) graphite

Which of these elements consist of a giant structure of atoms joined by covalent bonding?

(i) graphite

(ii) sulfur

(iii) diamond

(iv) iodine

Calculate the volume of oxygen gas formed on strongly heating 3.40 g sodium nitrate which decomposes according to this equation:

2NaNO_3(s) -> 2NaNO_2(s) + O_2(g)

Assume that the volume of 1 mol of any gas is 24 000 cm³ under the conditions of the experiment.

What is the electronic configuration of sulfide? 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.

E represents an atom of an element in the equation: E_(g) -> E⁺_(g) + e^– Which of these statements is/are true:

(i) the element must be a metal

(ii) the enthalpy change for this process is the first ionisation energy of the element

(iii) the element must be a gas at room temperature.

(iv) this process occurs in a mass spectrometer used to analyse the element