Chemistry Random Retrieval Y12

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:

Name the alkene CH₃CH(CH₃)CH=CHCH₃.

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 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

What is the oxidation number of FLUORINE in

F₂O

The total heat capacity of a calorimeter is 2000 J K^-1.

The standard enthalpy of combustion of propane is -2200 kJ mol^-1

Calculate the expected temperature rise on heating the calorimeter by burning 0.0500 mol of fuel from a propane burner assuming that all the energy heats the calorimeter.

Take care with units.

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

Zinc conducts electricity at room temperature because:

(i) the metal is solid

(ii) zinc is a d-block element

(iii) the atoms in the structure are in contact with each other

(iv) the bonding electrons are delocalised

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

(i) helium

(ii) oxygen

(iii) hydrogen

(iv) butane

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 changes are redox reactions?

(i) NaCl_(s) + H₂SO_4(l) -> HCl_(g) + NaHSO_4(s)

(ii) NH_3(g) + HCl_(g) -> NH₄Cl_(s)

(iii) CaCO_3(s) -> CaO_(s) + CO_2(g)

(iv) 2HBr_(g) + H₂SO_4 (l) -> Br_2(l) + SO_2(g) + 2H₂O_(l)

In the half equation: MnO₄^- _(aq) + 8H⁺_(aq) + ne^- -> Mn²⁺_(aq) + 4H₂O_(l) the value of n 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?

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 compounds is an acid?

Which of these processes are endothermic?

(i) water freezing

(ii) ethanol evaporating

(iii) steam condensing

(iv) wax melting

Which one of the following is the electron configuration of a group 2 metal atom?

What is the bond angle found in SO₄^2-?

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

The particle with 3 protons, 4 neutrons and 2 electrons is a:

The value that you obtain for the enthalpy of combustion Δ_cH of liquid ethanol using mean bond enthalpies is different from the value obtained experimentally, or by using enthalpy of formation Δ_fH of liquid ethanol.

What is the most significant reason for this?

Using enthalpies of formation Δ_fH, calculate the enthalpy change for the following esterification reaction.

CH₃COOH_(l) + C₂H₅OH_(l) => CH₃COOCH₂CH_3(l) + H₂O_(l)

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.

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.

Chlorine disproportionates when it reacts with:

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

What is the oxidation number of NITROGEN in

NaNH₂

What is the oxidation number of SULFUR in

SO₄^2-

What is the oxidation number of CARBON in

C₂H₆

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

Across period 2 from lithium to neon, the first ionisation enthalpy (energy) of:

(i) oxygen is higher than that of neon

(ii) oxygen is higher than that of nitrogen

(iii) boron is higher than that of beryllium

(iv) beryllium is higher than that of lithium

Choose one of the following options:

Choose one of the following options:

Choose one of the following options:

Which of these organic compounds show a broad absorption peak caused by hydrogen bonding affecting a functional group.

(i) propanol

(ii) propanal

(iii) propanoic acid

(iv) propanone

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:

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 product of the reaction of but-2-ene with steam in the presence of a phosphoric acid catalyst?

How many monosubstitution products can be formed when butane reacts with chlorine?