Density will be mass/volume= 0.2/500 = 0.0004
Answer: The mass of the sample will be 1417.7 grams.
Explanation:
We are given:

This means that 1 mole of NaCl has an enthalpy of fusion of 30.2 kJ
1 mole of NaCl has a mass of 58.44 grams.
So, 30.2 kJ of heat is require for a mass 58.44 grams of NaCl
So, 732.6 kJ of heat will be required for =
= 1417.65 grams of NaCl.
Hence, the mass of NaCl sample will be 1417.7 grams.
the law of thermodyanamic is the restatement of the law of conservation of energy
Answer:
Some metals can be extracted from compounds by heating with carbon atom because they are less reactive than carbon and some metals cannot be extracted because they are more reactive than carbon atom.
Explanation: If the metal is less reactive than carbon atom so the carbon atoms make bond with oxide or other atom present with metal and the metal is free from that oxide or that element. But if the reactivity of metal is higher than carbon is unable to remove the oxide or element.