Theory

CH20 - NITROGEN COMPOUNDS

Oxygen is a Group 16 element. (a) (i) Write equations for the following reactions. • sodium and oxygen • sulfur and oxygen $\text{.............

2024 Winter

3

Theory

CH20 - NITROGEN COMPOUNDS

(a) Nitrogen is found in inorganic compounds such as nitrogen oxides (NO\(_x\)), nitrates and nitric acid.(i) Identify one natural and one man-made oc...

2024 Winter

3

Theory

CH20 - NITROGEN COMPOUNDS

(a) \( NH_3(g) \) reacts with \( HCl(g) \) to produce \( NH_4Cl(s) \), as shown.\[ NH_3(g) + HCl(g) \rightarrow NH_4Cl(s) \]Draw a diagram to show the...

2024 Summer

2

Theory

CH20 - NITROGEN COMPOUNDS

Nitrogen, $N_2$, is generally an unreactive molecule but it does react under certain conditions. (a) Give two reasons to explain the lack of reactivi...

2024 Spring

4

Theory

CH20 - NITROGEN COMPOUNDS

(a) Identify compound U which contains only three elements............................................................ [1](b) Describe the reagents an...

2024 Winter

2

Theory

CH20 - NITROGEN COMPOUNDS

(a) An aqueous solution of phenol, $C_6H_5OH$, is acidic at 298K.Explain why phenol is more acidic than water............................................

2024 Winter

2

Theory

CH20 - NITROGEN COMPOUNDS

Amino acids are molecules that contain —NH₂ and —COOH functional groups.Glycine, $H_2NCH_2COOH$, is the simplest stable amino acid.(a) The isoel...

2024 Spring

2

Theory

CH20 - NITROGEN COMPOUNDS

(a) State the relative basicities of phenylamine, $\text{C}_6\text{H}_5\text{NH}_2$, benzylamine, $\text{C}_6\text{H}_5\text{CH}_2\text{NH}_2$, and am...

2024 Summer

1

Theory

CH20 - NITROGEN COMPOUNDS

(a) Isomer P and isomer Q have identical physical and chemical properties, with the exception of two specific properties. One of these two properties ...

2024 Winter

3

Theory

CH20 - NITROGEN COMPOUNDS

A reaction scheme is shown in Fig. 7.1.The reagents needed for reaction 2 and reaction 3 are stated.Reaction 5 takes place when $C_2H_5NH_2$ is mixed ...

2024 Winter

1

MCQ

CH3 - CHEMICAL BONDING

Which molecule contains six bonding electrons?

2017 Summer

2

MCQ

CH1 - ATOMS, MOLECULES & STOICHIOMETRY

The mass spectrum of a sample of lithium shows that it contains two isotopes, $^6\text{Li}$ and $^7\text{Li}$.The isotopic abundances are shown in the...

2017 Summer

2

MCQ

CH1 - ATOMS, MOLECULES & STOICHIOMETRY

A sports medal has a total surface area of 150 cm$^2$. It was evenly coated with silver by electrolysis. Its mass increased by 0.216 g.How many atoms ...

2017 Summer

2

MCQ

CH2 - ATOMIC STRUCTURE

Which property of an atom does not affect its first ionisation energy?

2017 Summer

2

MCQ

CH3 - CHEMICAL BONDING

Which molecule has the largest overall dipole?

2017 Summer

1

MCQ

CH4 - STATES OF MATTER

The complete combustion of 2 moles of a straight chain alkane produces 400 dm^3 of carbon dioxide measured at 301 K and 1 \times 10^5 Pa. Carbon dioxi...

2017 Summer

2

MCQ

CH5 - CHEMICAL ENERGETICS

Which expression gives the standard enthalpy change of combustion of methane?

2017 Summer

1

MCQ

CH6 - ELECTROCHEMISTRY

Solutions containing chlorate(I) ions are used as household bleaches and disinfectants. These solutions decompose on heating as shown. $$3ClO^- \righ...

2017 Summer

2

MCQ

CH6 - ELECTROCHEMISTRY

When $K_2MnO_4$ is dissolved in water, the following reaction occurs:$aMnO_4^{2-}(aq) + bH_2O(l) \rightarrow cMnO_4^{-}(aq) + dMnO_2(s) + eOH^{-}(aq)$...

2017 Summer

2

MCQ

CH7 - EQUILIBRIA

Methanol can be produced from hydrogen and carbon monoxide.$2H_2(g) + CO(g) \rightleftharpoons CH_3OH(g)$What is the expression for $K_p$ for this rea...

2017 Summer

3