Chemistry Random Retrieval Y12

Which of these alkenes shows E/Z isomerism?

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

What is made by heating propan-1-ol under reflux with excess of a hot acidic solution of potassium dichromate(VI) and then distilling off the product?

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

Which of these sets of properties is that of an ionic compound?

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

At room temperature, in the crystal lattice of an ionic compound the ions are:

(i) arranged symmetrically

(ii) uncharged

(iii) held together by electrostatic forces

(iv) stationary

Steel and graphite are similar in that they both.

(i) conduct electricity

(ii) are dark grey/black when powdered

(iii) can have high tensile strength

(iv) are brittle

What mass of silver is displaced from aqueous silver nitrate solution by 4.00 g magnesium?

(Relative atomic masses: Mg = 24.3, Ag = 108)

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 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

Which of these materials owe their strength to intermolecular forces?

What is the bond angle found in methane?

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 filled orbitals are there in the neon atom?

How many p electrons are there in the outer shell of a halogen atom?

What is the electron configuration of sulfur?

How many neutrons are there in an atom of boron with mass number 9 and atomic number 4?

Which of these are examples of heterogeneous equilibria?

(i) CaCO_3(s) <=> CaO_(s) + CO_2(g)

(ii) Fe²⁺_(aq) + Ag⁺_(aq) <=> Fe³⁺_(aq) + Ag_(s)

(iii) 3Fe_(s) + 4H₂O_(g) <=> Fe₃O_2(s) + 4H_2(g)

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

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

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

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.

Calculate the enthalpy change for the formation of one mole of hydrogen chloride gas from its elements given these average bond enthalpies: H-H bond enthalpy = 435 kJ mol^-1, Cl-Cl bond enthalpy = 243 kJ mol^-1 and H-Cl bond enthalpy = 432 kJ mol^-1

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

All the oxides of the metals Mg, Ca, Sr and Ba:

(i) are basic

(ii) consist of giant structures of ions

(iii) form nitrates when they react with dilute nitric acid

(iv) are freely soluble in water

What is the electron configuration of a magnesium atom?

What is the oxidation number of OXYGEN in hydrogen peroxide

H₂O₂

What is the oxidation number of CARBON in

CO₂

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 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

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?

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

This shows that carbon dioxide molecules:

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:

An alcohol consists of 64.9% carbon, 13.5% hydrogen and 21.6% oxygen.

What is the molecular formula of the compound? (Relative atomic masses: C = 12, H = 1, O = 16)

The reaction that has the greatest atom economy is:

Name the alkene CH₃CH(CH₃)CH=CHCH₃.

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: