Phase changes are physical changes (Andrew Rader Studios. 1997-2015) Phase changes are not chemical changes. (Andrew Rader Studios. 1997-2015) The following equations do not involve chemical changes as no new products are being formed, the substances are changing state which is a physical change: • Melting: H2O(s) > H2O(l) • Sublimation: H2O(s) > H2O(g) • Freezing: H2O(l) > H2O(s) Melting an ice cube is a reversible reaction as the chemical composition of H2O is not changed. Only the state is changed from solid to liquid by applying heat, which can be changed back by lowering the temperature enough. There are however some physical changes that cannot be reversed, for example, cracking an egg and grinding a wooden spoon. They both undergo physical …show more content…
2000-2016) In this reaction, there is a physical change as there is a change in the texture and colour of Fe. This reaction involves a chemical change as well; a new substance is formed. 2. Aluminum metal dissolving in an aqueous solution of sulfuric acid to form hydrogen gas bubbles and a solution of aluminum sulfate. Aluminum (s) + Sulfuric acid (aq) > Hydrogen (g) + Aluminum sulfate (aq) 2 Al (s) + 3 H2SO4 (aq) > 3 H2 (g) + Al2(SO4)3 (aq) This reaction undergoes physical and chemical changes, there is a chemical change as there are new products formed and a physical change as there are changes in state. 3. The reaction between silver nitrate and sodium chloride to form sodium nitrate and silver chloride. AgNO3 (aq) + NaCl (aq) → NaNO3 (aq) + AgCl (s) This reaction undergoes physical changes as there is a change in state and also there is a change in colour, after the reaction occurs, a white precipitate is formed. The reaction also undergoes a chemical change as 2 new products are formed. TASK …show more content…
This suggests that the intermolecular forces between molecules within an ionic compound are much stronger than the intermolecular forces between molecules within a covalent compound. The densities of the ionic compounds in table 1 are also higher than the densities in table 2. Due to ionic compounds having stronger intermolecular forces than covalent compounds, the volume of the ionic compound would be less than the volume of the covalent compound. Density=Mass/Volume, so a lower volume would result in a higher density. (Santosh Agray.