Period Table & Energy Random Retrieval

Using enthalpies of combustion Δ_cH, calculate the enthalpy change for the cracking of butane:

C₄H_10(g) => C₂H_6(g) + C₂H_4(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.

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.

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.

What are the standard conditions for measuring standard enthalpy changes?

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 oxidation number of CARBON in methanal

CH₂O

What is the oxidation number of BROMINE in

BrO^-

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

In the periodic table the elements are arranged in order of:

(i) atomic number

(ii) mass number

(iii) number of protons in the nucleus

(iv) number of protons and neutrons in the nucleus.

In which of these pairs do both entities have the same electron configuration?

(i) Li and Na

(ii) Na⁺ and Mg²⁺

(iii) F^- and Cl^-

(iv) Cl^- and Ar