Explain the following statements : (i) Sodium chloride pieces are har

1.	Explain the following statements : (i) Sodium chloride pieces are harder than sodium metal. (ii) Copper is ductile and malleable but brass is not. (iii) Latent heat of fusion of solid carbon dioxide is much less than that of silicon dioxide. (iv) Water has its maximum density near 277K. (v) Ice floats on surface of water near the melting point.
Answer» (i) It has stronger electrostatic forces than metallic bond in sodium. (ii) Copper is a pure element while brass is an alloy. Pure metal is more malleable. (iii) SiO₂ has covalent bonds while CO₂ has only Van der waal’s forces (molecular solid). Hence SiO₂ has higher heat of fusion. (iv) Below 277 K and above 277 K, water expands hence its volume increases, density decreases and is maximum at 277 K (v) At 0°C or 273 K, its density is less than that of water hence floats.

Explain the following statements : (i) Sodium chloride pieces are harder than sodium metal. (ii) Copper is ductile and malleable but brass is not. (iii) Latent heat of fusion of solid carbon dioxide is much less than that of silicon dioxide. (iv) Water has its maximum density near 277K. (v) Ice floats on surface of water near the melting point.

Answer»

(i) It has stronger electrostatic forces than metallic bond in sodium.

(ii) Copper is a pure element while brass is an alloy. Pure metal is more malleable.

(iii) SiO₂ has covalent bonds while CO₂ has only Van der waal’s forces (molecular solid). Hence SiO₂ has higher heat of fusion.

(iv) Below 277 K and above 277 K, water expands hence its volume increases, density decreases and is maximum at 277 K

(v) At 0°C or 273 K, its density is less than that of water hence floats.