Category: Chemistry

2.82g of lithium carbonate was dissolved in deionised water and made up to 250cm³ in a volumetric flask.

10.0cm³ samples were titrated against hydrochloric acid solution of concentraion 0.100 mol dm^-3.

A mean titre of 28.70cm³ 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!)

Calculate the pH of a solution created by the addition of 49.0cm³ 0.250 mol dm^-3 barium hydroxide (Ba(OH)₂) solution to 100 cm³ 0.250 mol dm^-3 chloric (VII) acid solution.

Remember to give your answer to 3 sig.fig.

Calculate the pH of a solution created by the addition of 20.0cm³ 0.200 mol dm^-3 potassium hydroxide solution to 50.0 cm³ 0.100 mol dm^-3 nitric 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 28.05cm³ of 0.100 mol dm^-3 solution of potassium hydroxide was required to just neutralise a 25.00 cm³ sample of phosphoric acid solution. Calculate the concentraion of the phosphoric acid solution.

The equation for the reaction is

3KOH_(aq)+H₃PO_4(aq)=>K₃PO_4(aq)+3H₂O_(aq)

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 28.80cm³ of 2.00 mol dm^-3 solution of potassium carbonate was required to just neutralise a 50.00 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 21.85cm³ of 0.200 mol dm^-3 solution of potassium hydroxide was required to just neutralise a 10.00 cm³ sample of phosphoric acid solution. Calculate the concentraion of the phosphoric acid solution.

The equation for the reaction is

3KOH_(aq)+H₃PO_4(aq)=>K₃PO_4(aq)+3H₂O_(aq)

By titration, it was found that an average titre of 19.10cm³ of 0.250 mol dm^-3 solution of sulfuric acid was required to just neutralise a 10.00 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 22.25cm³ of 0.100 mol dm^-3 solution of hydrochloric acid was required to just neutralise a 20.00 cm³ sample of lithium hydroxide solution. Calculate the concentraion of the lithium hydroxide solution.

The equation for the reaction is

LiOH_(aq)+HCl_(aq)=>LiCl_(aq)+H₂O_(aq)

Calculate the concentration of HCl in a solution of volume 1.25dm³ that contains 460 g of HCl

H=1 Cl=35.5

Calculate the concentration of Al₂(SO₄)₃ in a solution of volume 2.26dm³ that contains 500 g of Al₂(SO₄)₃

S=32.1 Al=27.0 O=16.0

Calculate the concentration of barium nitrate in a solution of volume 19.85cm³ that contains 4.82 g of barium nitrate

Ba=137.3 N=14.0 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 cm³ that would contain 0.450 mol of Ag⁺ ions if the concentration of the solution is 0.400 mol cm^-3

Calculate the volume of solution in cm³ that would contain 1.12 mol of ammonia if the concentration of the solution is 6.50 mol cm^-3

Calculate the volume of solution in dm³ that would contain 0.200 mol of NO₃^- ions if the concentration of the solution is 1.85 mol dm^-3

Calculate the number of moles of silver nitrate in a solution of volume 1.10 dm³ and a concentration of 1.30 mol dm^-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 1.20 mol of sulfur hexafluoride if the gas is at a temperature of 750K and a pressure of 150kPa

Calculate the volume of gas (in cm³) of 0.175 mol of nitrogen if the gas is at a temperature of 800K and a pressure of 1000kPa

Calculate the volume of gas (in m³) of 7.00 mol of hydrogen chloride if the gas is at a temperature of 3000K and a pressure of 1000kPa

Calculate the number of moles of gas present at r.t.p in 700 cm³ of butane.

Calculate the number of moles of gas present at r.t.p in 6.6 m³ of helium.

Calculate the number of moles of gas present at r.t.p in 18.0 dm³ of propane.

Calculate the number of moles of gas present at r.t.p in 3000 cm³ of oxygen.

Calculate the number of moles of gas present at r.t.p in 0.600 dm³ of fluorine.

Calculate the number of moles of gas present at r.t.p in 0.200 m³ of methane.

Calculate the number of moles of gas present at r.t.p in 40.0 dm³ of hydrogen chloride.

Calculate the number of moles of hydrogen if you have 6.00 g of hydrogen

H=1.0

Calculate the number of moles of phosphorus (V) oxide (P₄O₁₀) if you have 80.0 g of phosphorus (V) oxide (P₄O₁₀)

P=31.0 O=16.0

Calculate the number of moles of F₂ if you have 9.50 g of F₂

F=19.0

Calculate the number of moles of Mg(OH)₂ if you have 87.5 g of Mg(OH)₂

Mg=24.3 H=1.00 O=16.0

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

C=12.0 H=1.0

Calculate the mass of phosphorus (V) oxide (P₄O₁₀) that you would have if you had 1.25 mol of phosphorus (V) oxide (P₄O₁₀)

P=31.0 O=16.0

Calculate the mass of aluminium sulfate that you would have if you had 0.860 mol of aluminium sulfate

S=32.1 Al=27.0 O=16.0

Calculate the mass of sodium that you would have if you had 3.00 mol of sodium

Na=23.0

Calculate the mass of Ba(NO₃)₂ that you would have if you had 0.900 mol of Ba(NO₃)₂

Ba=137.3 N=14.0 O=16.0

Calculate the mass of FeSO₄ . 7H₂O that you would have if you had 3.00 mol of FeSO₄ . 7H₂O

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

Barium hydroxide solution will neutralise hydrochloric acid according to the equation

Ba(OH)₂+2HCl =>BaCl₂+2H₂O

If 1 dm³ of 0.1 mol dm^-3 Ba(OH)₂ neutralises 0.5 dm³ of dilute hydrochloric acid, what is the concentration of the acid?

What volume (measured under r.t.p. of oxygen will be produced by complete thermal decomposition of 4.25g of sodium nitrate?

2NaNO₃ => 2NaNO₂ + O₂

How many moles of molecules are present in 2.40 dm³ of argon? (all volumes measured at r.t.p.)

The mass of 0.250 moles of LiOH is:

Ca₃N₂

silver nitrate

zinc oxide

How many carbon-12 atoms would have the same mass as 1 Ag atom? Enter a whole number.

Neon (accurate relative atomic mass = 20.18) is made up of three isotopes: Ne-20, Ne-21 and Ne-22.

One of these makes up 90.92% of the element. Which one?

Identify the element (write the symbol) if an atom of Z is one-third of the mass of a ¹²C atom.

What is the systematic name of the following molecule?

CH₃CH₂CH₂C(NH₂)CHCH₃

Which of these molecules does NOT consist of one or more chains of amino acids?

(i) The hormone insulin

(ii) The filaments in muscle fibres

(iii) The enzyme in saliva, amylase

(iv) The genetic material, DNA

Which of these compounds are chiral?

(i) propan-1-ol,

(ii) propan-2-ol,

(iii) butan-1-ol,

(iv) butan-2-ol

Consider the values of the equilibrium constant for this reversible reaction:

H_2(g) +I_2(g) <=> 2HI_(g)

Temperature: 500K, value of K_c = 160

Temperature: 1000K, value of K_c = 54.

This information shows that:

(i) HI decomposes rapidly at 500 K

(ii) Raising the temperature causes the equilibrium to shift to the left

(iii) Raising the pressure causes the equilibrium to shift to the right

(iv) The reaction is exothermic

Consider the following equilibrium:

2SO_2(g) + O_2(g) <=>2SO_3(g)

8.00 mol of SO₂ was mixed with 5.00 mol of O₂ and the mixture sealed in a heated vessel of volume of 1.00 dm³. The mixture was left until no further observable change in composition took place. At this point, 2.00 mol of O₂ was present in the mixture and the pressure was recorded as 200 kPa.

Calculate the value K_c (in units: mol^-1 dm³) under these conditions.

Look at the chemical equation below.

CH_4(g) + H₂O_(g)=> CO_(g)+ 3H_2(g)

By selecting the appropriate data from the ‘Selection of Thermodynamic Data’ in TOOLS, calculate the enthalpy change ΔH^Ɵ for the process. Take care with states!

Which of the first-row d-block metals forms aqueous ions which are mauve in the +2 state, green in the +3 state, blue in the +4 state and yellow in the +5 state?

Which first-row d-block metal has the main oxidation state +2 and forms colourless compounds?

Which first-row d-block metal forms hydrated ions in the +3 state which undergo a ligand exchange reaction to form a deep red complex ion with thiocyanate ions, SCN^-.

Thinking carefully about the definitions of anode and cathode in electrochemical cells, an anode is defined as (CARE!):

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?

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)

Under standard conditions, can Mg²⁺_(aq) be reduced to Mg_(s) by Ca_(s)?

What is the value of E^ϴcell/V observed for a cell constructed from the following half-cells. (These are the half-cells that are put together in a car battery (6 cells in series)?

PbSO_4(s) + 2e^- <=> Pb_(s) + SO₄^2-_(aq) E^ϴ/V = -0.36

PbO_2(s) + SO₄^2-_(aq)+4H_(aq) + 2e^- <=> PbSO_4(s) + 2H₂O(l) E^ϴ/V = +1.69

What is the value of E^ϴcell/V observed for a cell constructed from the following half-cells? These half-cells are those involved in Hydrogen Fuel Cells when operated in acidic conditions?

H⁺_(aq) + e^-<=> ½H_2(g) (acidic conditions) E^ϴ/V = 0.00

O_2(g)+ 4H⁺_(aq) + 4e^-<=>2H₂O_(g) (acidic conditions) E^ϴ/V = +1.23

What is the value of E^ϴcell/V observed for a cell constructed from the following half-cells?

Fe³⁺_(aq) + e^- <=> Fe²⁺_(aq) E^ϴ/V = +0.77

MnO₄^-_(aq) + 8H⁺_(aq) + 5e^- <=> Mn²⁺_(aq) + 4H₂O_(aq) E^ϴ/V = +1.51

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

If pressures are measured in pascals (Pa) what are the units of K_p for this equilibrium:

2H_2(g) + O_2(g) <=> 2H₂O_(g)

By inspection of this experimental data, what is the rate equation for this reaction?

Which of these are examples of kinetic stability?

(i) A solution of hydrogen peroxide can be stored at room temperature

(ii) Hydrogen does not ignite in air at room temperature

(iii) Aluminium does not corrode in moist air

(iv) Magnesium oxide does not decompose on heating

The activation energy for the reaction of sodium thiosulfate with acid is close to 50 kJ mol^-1. Mixing a measured volumes of sodium thiosulfate solution and hydrochloric acid at 30^oC produces a certain amount of sulfur in 120 seconds.

Repeating the experiment with all the conditions the same except the temperature is 40 ^oC produces the same amount of sulfur in:

This is the ¹H NMR spectrum of:

Which of these compounds are chiral?

(i) CH₂Cl₂

(ii) CH₂ClBr

(iii)CHCl₂F

(iv) CH₃CHClBr

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 organic compounds are all the bonds non-polar?

(i) 1-bromobutane

(ii) butene

(iii) butan-2-ol

(iv) butane

Step 1:

Which of these compounds are solids at room temperature?

(i) propane

(ii) propanoic acid

(iii) propylamine

(iv) 2-aminopropanoic acid

Which of the following molecules would you predict to be the most soluble in water?

Which types of change are involved in this sequence of changes (but not necessarily in the order listed)?

CH₃CH₂CH₂OH -> CH₃CH₂CHO -> CH₃CH₂CO₂H -> CH₃CH₂CO₂CH₂CH₃

(i) hydrolysis

(ii) esterification

(iii) acid-base

(iv) oxidation

The reaction of propanone with HCN in the presence of some KCN is an example of:

Which types of alcohol, when heated under reflux with acidified potassium dichromate(VI), turn the colour of the solution from orange to green?

Which of these formulae represents 2,2-dimethylpentane?

(i) CH₃C(CH₃)₂CH₂CH₂CH₃

(ii) CH₃CH₂C(CH₃)₂CH₂CH₃

(iii) CH₃CH₂CH₂C(CH₃)₂CH₃

(iv) CH₃CH₂CH₂CH₂CH(CH₃)₂

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 oxidation number of NITROGEN in

NH₃

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.

A chloride ion and an argon atom have the same:

(i) number of protons

(ii) number of electrons

(iii) atomic number

(iv) electron configuration

Which of these sets of properties is that of a substance which is molecular?

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.

In which of these elements are the atoms or molecules closely packed but free to move around sliding past each other at room temperature?

(i) mercury

(ii) argon

(iii) bromine

(iv) iodine

Which of these acids is only slightly ionised in aqueous solution?

(i) hydrochloric acid

(ii) nitric acid

(iii) sulfuric acid

(iv) ethanoic acid

In which of the following industrial conversions is a chemical species (atoms, molecule or ion) oxidised to give the element:

(i) iron ore oxide to iron

(ii) potassium iodate(V) to iodine

(iii) copper(II) sulfate to copper

(iv) sodium chloride to chlorine

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)

The ionic equation for a neutralisation reaction is:

Which of these gases behaves very much like an ideal gas at room temperature and pressure?

(i) helium

(ii) oxygen

(iii) hydrogen

(iv) butane

What is the bond angle found in BeCl₂?

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

An element M has two electrons in its outer shell. An element X has seven electrons in its outer shell. What is the likely formula of the compound of X and Y?

How many partially filled orbitals are there in the nitrogen atom?

How many filled orbitals are there in the neon atom?

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.

The synthesis of sulfur trioxide takes place at 380 ^oC in the presence of a catalyst made from vanadium(V) oxide.

2SO_2(g) + O_2(g) <=> 2SO_3(g) Standard enthalpy change = -297 kJ mol^-1

Reasons for not choosing a lower temperature are that:

(i) the product condenses to a solid at a lower temperature

(ii) the proportion of SO_3(g) at equilibrium falls if the temperature falls

(iii) the reaction is exothermic

(iv) the catalyst is ineffective at lower temperatures

The reaction of nitrogen with hydrogen to form ammonia is exothermic. Which of these changes increases the proportion of ammonia in an equilibrium mixture of nitrogen, hydrogen and ammonia.

(i) raising the pressure at constant temperature

(ii) raising the temperature at constant pressure

(iii) decreasing the volume at constant temperature

(iv) adding a catalyst

What are the standard conditions for measuring standard enthalpy changes?

Which of the following properties increase from left to right across the series: AgCl - AgBr - AgI?

(i) intensity of colour

(ii) solubility in ammonia solution

(iii) ease of oxidation to the halogens

(iv) solubility in aqueous ammonia

Iodine oxidises thiosulfate ions, S₂O₃^2 -, to S₄O₆^2- . What is the oxidation number (O.N.) change for each sulfur atom?

The electron configuration of a chloride ion is:

Bubbling carbon dioxide into an aqueous solution of calcium hydroxide produces a white precipitate of:

What is the oxidation number of FLUORINE in

F₂O

What is the oxidation number of SULFUR in

SO₃

Which of these true statements help to explain why the values of the first ionisation enthalpies (energies) of the group 1 metals fall down the group from lithium to caesium?

(i) Down the group, the outer electron gets further from the nucleus

(ii) The charge on the nucleus increases down the group

(iii) Greater shielding means that the attraction between the nucleus and the outer electron reduces down the group

(iv) In all the atoms the outer electron is an s-electron

Infra-red absorption ranges for some bonds are as follows:

C-H, 2850 - 3300 cm^-1

C=C, 1620 - 1680 cm^-1

C=O, 1680 - 1750 cm^-1

C-O, 1000 - 1300 cm^-1

O-H (alcohols), 3230 - 3550 cm^-1

O-H (acids), 2500 - 3000 cm^-1

The IR spectrum of propanal has one particularly strong absorption peak

This can be expected to be at:

The mass spectrum of copper has two significant peaks. The peak at 63 has a relative abundance of 69 and the peak at 65 has a relative abundance of 31.

This shows that the relative atomic mass of copper is:

Which of these pairs of compounds react to form 2-bromopropane as one of the products?

(i) prop-1-ene and hydrogen bromide at room temperature

(ii) propane and bromine in ultraviolet light

(iii) propan-2-ol on heating with sodium bromide

(iv) propan-1-ol and hydrogen bromide on heating

Three halogenoalkanes differ in the rate with which they react with aqueous sodium hydroxide. The order of the rates of reaction is:

Heating butan-1-ol with a mixture of sodium bromide and concentrated sulfuric acid produces 1-bromobutane. During the preparation the reaction mixture turns orange due to the formation of:

Why is ethanol a liquid while propane is a gas? (Relative atomic masses: C = 12, H = 1, O = 16)

The reaction that has the greatest atom economy is:

What is the name for this structure:

CH₃CH(CH₃)CH(CH₃)CH₂CH₃?

Burning a hydrocarbon fuel such as methane gas in a limited supply of air is dangerous because under these conditions one of the products is:

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

What is the mechanism for the reaction of bromine with prop-1-ene?

Adding a compound X, C₄H₁₀O, drop by drop to a hot acidic solution of potassium dichromate(VI) and allowing the product to distil off as it forms, produces a compound which gives a silver mirror with Tollens solution. This shows that X could be:

(i) CH₃CH₂CH₂CH₂OH

(ii)CH₃CH₂CHOHCH₃

(iii)CH₃CH(CH₃)CH₂OH

(iv) CH₃CH₂OCH₂CH₃

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

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

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

What is the mass of 0.00400 mol of sodium hydrogensulfate?

What is the bond angle found in BF₃?

Which of the following molecules is/are examples of 2^o amines?

(i) 

(ii)

(iii) 

(iv) 

Which of these polymers would you expect to have the strongest intermolecular (interchain) forces as a result of the presence of polar covalent bonds?

The reaction of hydrogen gas with nitrogen monoxide gas is first order with respect to H_2(g) and second order with respect to NO_(g). It follows that:

(i) rate = k[H_2(g)][NO_(g)]²

(ii) doubling the concentration of NO_(g) increases the rate by a factor of 4

(iii) the overall order of reaction is 3

(iv) halving the concentration of hydrogen reduces the rate by a factor of 1.

What is the value of the rate constant, k for this reaction at this temperature?

Consider the following equilibrium for the Haber-Bosch process:

3H_2(g) + N_2(g) <=>2NH_3(g)

32.0 mol of H₂ was combined with 12.0 mol of N₂ and the mixture sealed and pressurised in a vessel of volume 2.00 dm³. The mixture was left until no further observable change in composition took place. At this point, 4.00 mol of NH₃ was found to be present in the mixture. The pressure was recorded as 200 000 kPa.

Calculate the value of K_c (in units: mol^-2 dm⁶) under these conditions.

Look at the chemical equation below.

2NaHCO_3(s)=> Na₂CO_3(s)+ H₂O_(g)+ CO_2(g)

Calculate the temperature at which this process becomes feasible.

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

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 metal forms a reddish oxide in the +1 state which dissolves in dilute sulfuric acid to give a blue solution and a red-brown precipitate?

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

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

BrO₃^- + H⁺ + e^- => Br^- + H₂O

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

Dilute hydrochloric acid reacts with:

(i) zinc to form zinc chloride and hydrogen

(ii) copper(II) oxide to form copper(II) chloride and water

(iii) zinc carbonate to form zinc chloride, carbon dioxide and water

(iv) copper to form copper(II) chloride and hydrogen

Which of these reactions is an acid-base reaction?

Which of these molecules are overall non-polar?

(i) H₂O

(ii) CO₂

(iii) SO₂

(iv) CCl₄

Which of these sets of properties is that of a substance which is molecular?

During the electrolysis of molten sodium chloride:

(i) sodium metal forms at the negative electrode

(ii) sodium ions are reduced at the cathode

(iii) chloride ions lose electrons at the positive electrode

(iv) chlorine atoms are given off as a gas at the anode

Sodium hydride reacts with water:

NaH_(s) + H₂O_(l) -> NaOH_(aq) + H_2(g)

What is the concentration of a solution of sodium hydroxide formed when 0.600 g sodium hydride reacts with water and the solution is diluted to 100 cm³?

How many complete sub-shells are there in the phosphorus atom?

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.